JP3480669B2 - Particle passing position detector - Google Patents

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 the passage position of particles, for example, a particle passage position detection applied to a particle counting device for counting the number of particles passing through a channel by discriminating the particle size. Regarding the device.

[0002]

2. Description of the Related Art As a conventional particle counting device, as shown in FIG. 18, a laser beam La is applied to an internal flow path of a flow cell 100, and the particle is emitted when the particle passes 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
4, there is known a light scattering type particle counting device for counting the number of particles passing through the internal flow path by discriminating the particle size.

The photoelectric conversion element 102 outputs a pulsed voltage corresponding to the scattered light Ls emitted by the particles when the particles pass through the internal flow path. 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 as being larger than the predetermined particle size. This 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 device 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 size is erroneously performed. There is a problem of doing. The laser light intensity of the internal flow path is generally highest in the center of the laser beam,
In many cases, the distribution deviates from the center and becomes lower toward the ends (almost Gaussian distribution).

Therefore, even if the particle size and optical properties of the particles are the same, the intensity of the scattered light Ls of the particles is different between when passing through the end portion of the laser beam and when passing through the central portion. 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 problems of the prior art. The object of the present invention is to solve the conventional problems as long as the passage position of particles is known. In view of the above, an object of the present invention is to provide a particle passage position detecting device capable of detecting the position of a flow path through which particles have passed.

[0007]

In order to solve the above-mentioned problems, the invention according to claim 1 forms a measurement region by irradiating a flow cell formed of a transparent member in a bent shape with a laser beam on a flow path of the flow cell. A laser light source, a condensing unit that has an optical axis that coincides with the central axis of the flow channel, and condenses the scattered light of particles generated in the measurement region, and the scattered light condensed by the condensing unit. Light detection means composed of a plurality of photoelectric conversion elements for receiving light, voltage detection means for detecting output signals of the plurality of photoelectric conversion elements, and the measurement area where particles have passed by comparing the output signals of the voltage detection means with each other. The position detecting means for outputting the passing position information of is included.

According to a second aspect of the present invention, in the particle passing position detecting device according to the first aspect, in the light detecting means including the plurality of photoelectric conversion elements, each light receiving surface is perpendicular to the central axis of the flow path, and The photoelectric conversion element array includes 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 flow path and the laser optical axis.

According to a third aspect of the present invention, in the particle passing position detecting device according to the first aspect, the photodetecting means composed of the plurality of photoelectric conversion elements is V × H in length and width (both V and H). Each of the light receiving surfaces is perpendicular to the central 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 light having a central axis of the laser light. Concentrating means for concentrating scattered light of particles generated in the measurement region having an axis, a trap located on the optical axis of the condensing means, and receiving scattered light condensed by the condensing means Photodetection means consisting of a plurality of photoelectric conversion elements, voltage detection means for detecting the output signals of the plurality of photoelectric conversion elements, the output signal of the voltage detection means is compared with each other of the measurement region through which 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 passage position detecting device according to the fourth aspect, the light detecting means including the plurality of photoelectric conversion elements has each light receiving surface perpendicular to the laser optical axis and a flow path. Is a photoelectric conversion element array including 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.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. Here, FIG. 1 shows the first of the present invention.
2 is a configuration diagram of a particle passage position detecting device according to the embodiment, FIG. 2 is a plan sectional view of a measurement region irradiated with laser light in FIG. 1, and FIG. 3 is a longitudinal sectional view of a measurement region irradiated with laser light in FIG. 4 to 8 are diagrams showing the light receiving state (a) of the photoelectric conversion element array and the output waveform (b) at that time in FIG. 1, FIG. 9 is a diagram showing a particle information reference table, and FIG. 10 is a diagram showing 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 vertical cross-sectional views of the measured region, and FIG. 13 is a diagram showing the light receiving state (a) of the photoelectric conversion element array in FIG.

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

The flow cell 1 is made of a transparent member, has a linear flow path 1a of a predetermined length, and is bent as a whole.
The flow cell 1 has a quadrangular cross section and is formed in an L-shaped tubular shape as a whole. The central axis of the straight flow path 1a coincides with the X direction.

The reason for providing the linear flow path 1a having a predetermined length is as follows.
This is for making the flow of the test fluid laminar when the test fluid is flown through the flow cell 1. The conditions for obtaining the laminar flow include the viscosity of the test fluid, the length of the linear flow path, the cross-sectional shape and flow velocity of the flow path, 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 velocity 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 the laser light 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 linear flow path 1a coincident with the X direction.

Further, as shown in FIG. 2, the angle formed by 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 by the outer wall of the flow cell 1 and returning part of the reflected light 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 superimposed on the laser light La, which is not preferable.

If the laser light La can be guided to a predetermined position of the linear flow path 1a through the same material as the outer wall of the flow cell 1 so that the laser light La is not reflected by the outer wall of the flow cell 1, the predetermined angle θ is obtained. No need to set.

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

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

The optical axis of the laser light La and the flow cell 1
2 is set to a predetermined angle θ shown in FIG. 2, the light receiving surfaces of the photoelectric conversion elements 4a, 4b, 4c are
It may be inclined by a predetermined angle θ with respect to a plane perpendicular to the optical axis of the condensing optical system 3.

The processor 5 detects the peak values (pulse heights) Ea, Eb, Ec of the voltages output by the three photoelectric conversion elements 4a, 4b, 4c while the particles pass through the measurement region 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 the voltage detecting means, peak value detecting means 6a, 6b for detecting the peak values Ea, Eb, Ec of the voltages output by the photoelectric conversion elements 4a, 4b, 4c, respectively. , 6c are used, but not necessarily the peak value, for example, photoelectric conversion elements 4a, 4b, 4
The output voltage of c may be detected at the same timing, and the output voltage may be used for the subsequent arithmetic processing. Further, as the voltage detecting means, the output voltages of the photoelectric conversion elements 4a, 4b, 4c may be integrated for a predetermined time and output.

The position detecting means 7 comprises a computing section 7a and a storage section 7
First, the calculation unit 7a performs the following calculation 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 passage position detecting apparatus according to the first embodiment of the present invention constructed as above will be described. Since it is necessary to know the laser light intensity distribution of the measurement region M in advance, a method of measuring the laser light intensity distribution of the measurement region 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 waveforms of the photoelectric conversion elements 4a, 4b, 4c of the photoelectric conversion element array 4 vary depending on which position in the measurement region M the standard particles pass through. Then, the three photoelectric conversion elements 4a, 4b, 4
In the case of the photoelectric conversion element array 4 composed of c, there are five main possible passage patterns.

First, the standard particles are measured in the measurement area M shown in FIG.
Of light scattered by standard particles when passing through the center Mc of
The spot S of s appears only in the photoelectric conversion element 4b at the center of the photoelectric conversion element array 4, as shown in FIG.
At this time, the output waveforms of the photoelectric conversion elements 4a, 4b, 4c (relationship between time t and voltage E) are as shown in FIG. 4 (b). That is, only the photoelectric conversion element 4b outputs a substantially pulsed 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 (time t1 to time t2). However, the other photoelectric conversion elements 4a and 4c output only substantially level voltages (peak values Ea and Ec) corresponding to noise.

Next, the standard particles are measured in the measurement area M shown in FIG.
When passing through the one end Ms of the photoelectric conversion element array 4, the spot S of the scattered light Ls due to the standard particles appears only in 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 of each photoelectric conversion element 4a, 4b, 4c (relationship between time t and voltage E) is as shown in FIG. 5 (b). That is, only the photoelectric conversion element 4a has the measurement area M
Outputs a substantially pulsed voltage (peak value Ea) corresponding to the scattered light Ls of the standard particles that passes through one end Ms of the same for a certain time (time t3 to time t4), and the other photoelectric conversion element 4b,
4c is a substantially level voltage corresponding to noise (peak values Eb, E
Only output c).

Similarly, when the standard particles pass through the other end Ms (symmetrical to one end Ms) of the measurement region M shown in FIG. 3, the spot S of the scattered light Ls by the standard particles is as 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 waveforms (relationship between time t and voltage E) of the photoelectric conversion elements 4a, 4b, 4c are as shown in FIG. 6 (b). That is, only the photoelectric conversion element 4c passes through the other end Ms of the measurement region M for a certain time (time t3 to time t4), and the scattered light L of the standard particles is generated.
A substantially pulsed 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 value Ea, Eb) corresponding to noise.

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

Similarly, when the standard particles pass through the other path Mm (symmetrical to the one path Mm) of the measurement region 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 straddling the boundary between the photoelectric conversion elements 4b and 4c. At this time, the output waveform of each photoelectric conversion element 4a, 4b, 4c (relationship between time t and voltage E) is as shown in FIG. 8 (b). That is, the photoelectric conversion elements 4b and 4c pass through the other path Mm of the measurement region M for a certain time (time t5 to time t6) and have a substantially pulsed voltage (peak value Eb, corresponding to the scattered light Ls of the standard particles). E
c) is output, and the photoelectric conversion element 4a outputs only a substantially level voltage (peak value Ea) corresponding to noise.

Then, in the position detecting means 7, FIG.
When the spot S appears only in the central 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. Also, the calculation unit 7a
In, 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 almost 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 formed only on the photoelectric conversion element 4a at one end.
, Appears in the operation 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 very large value (Ea / Eb≈Ea / Eb≈
∞) is output and stored in the storage unit 7b. Similarly, the photoelectric conversion element 4c corresponding to the peak voltage Eb of the photoelectric conversion element 4b
Of the peak voltage Ec of Ec / Eb is calculated, and Ec≈Eb
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. 6A, the spot S is formed only on the photoelectric conversion element 4c at the other end.
, Appears in the operation 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. It is stored in the section 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 a very large value (Ec / Eb).
≈∞) is output and stored in the storage unit 7b.

Next, in the position detecting means 7, when the spot S appears across the boundary between the photoelectric conversion elements 4a and 4b as shown in FIG. 7 (a), the photoelectric conversion is performed in the calculation section 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, and since Ec <Eb, the ratio Ec / Eb is almost zero (Ec / Eb≈0). The value of is output and stored in the storage unit 7b.

Further, in the position detecting means 7, as shown in FIG. 8A, when the spot S appears across the boundary between the photoelectric conversion elements 4b and 4c 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 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.

The reference voltage is the photoelectric conversion element 4
b other than the peak voltage Eb of photoelectric conversion elements 4a, 4c
The peak voltages Ea and Ec may be the sum of the peak voltages (Ea + Eb + Ec). In short, not the absolute value of the peak voltage of the photoelectric conversion elements 4a, 4b, 4c but the ratio (ratio) of the peak voltage of each photoelectric conversion element 4a, 4b, 4c to the reference voltage is used to determine the spot S of the scattered light Ls by the standard particles. This is because it is more accurate to find the position of.

FIG. 9 shows the above five cases.
As shown in, the 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.
And 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, the particle information reference table is referred to thereby determine the passage position of the particle in the measurement region M in the Y direction. It can be identified from 5 types.

In addition to the above-mentioned five passage patterns, spots S are formed at the boundary between the photoelectric conversion element 4a and the photoelectric conversion element 4b or at the boundary between the photoelectric conversion element 4b and the photoelectric conversion element 4c.
Even when passing through the path of the measurement region M that is not uniform and appears across the photoelectric conversion element 4a and 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, Ratio of peak voltage Ec of photoelectric conversion element 4c to peak voltage Eb of 4b Ec / E
If b is known, the passing position of the particle in the measurement region 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, 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 configurations as those shown in FIG.

The light detecting means 14 has a vertical (Y direction) and a horizontal (Z direction).
Direction) 3 × 3 matrix photoelectric conversion elements D
₁₁ , D ₁₂ , D ₁₃ , D ₂₁ , ... D ₃₃ , and each light-receiving surface forms a YZ plane perpendicular to the central axis (X direction) of the flow path 11a.

The processing device 15 has peak values E ₁₁ , E ₁₂ , E ₁₃ , of output voltages of the photoelectric conversion elements D ₁₁ , D ₁₂ , D ₁₃ , D ₂₁ , ... D ₃₃ of 3 × 3. 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.
The output voltages of ₁₁ , D ₁₂ , and D ₁₃ are sampled in a time division manner to detect their peak values E ₁₁ , E ₁₂ , and E ₁₃ , and the peak value detecting means 16b detects 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.

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 of the scattered light Ls of the particles passing through the measurement region M at a certain time. . Further, the voltage detecting means is not necessarily a peak value, but may be, for example, photoelectric conversion elements D ₁₁ , D ₁₂ , D ₁₃ , D ₂₁ ,.
The output voltage of D ₃₃ may be detected at the same timing.
Further, as voltage detecting means, 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.
One of the voltages (for example, peak value E ₂₂ ) is selected from ₁₁ , E ₁₂ , E ₁₃ , E ₂₁ , ... E ₃₃ , and the ratio of this voltage to other peak values (E ₁₁ / _{E 22, E 12 / E 22} ......) is calculated, and then stores the result in the storage unit 17b, to create a particle information reference table similar to FIG.

Further, in the calculation unit 17a, the largest peak value is selected from the peak values E ₁₁ , E ₁₂ , E ₁₃ , E ₂₁ , ... E ₃₃ detected by the peak value detecting means 16a, 16b, 16c. The result may be stored in the storage unit 17b.

The operation of the particle passage position detecting device according to the second embodiment of the present invention having the above structure will be described. As shown in FIG. 10, a fluid containing particles is poured 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 are selected depending on which position of the measurement area M the particles pass through.
There are various output waveforms of D ₃₃ .

For example, when the 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 detection means 16a, 16b, 16c cause the particles to pass through the measurement area M. While passing, the output voltage of the photoelectric conversion elements D ₁₁ , D ₁₂ , D ₁₃ , D ₂₁ , ... D ₃₃ according to the scattered light Ls of the particles is sampled to detect the peak value.

In this case, the laser light intensity in the measurement region M has a distribution that the intensity is strongest in the central part and weakens toward the end part deviating from the central part (almost Gaussian distribution). Since the light intensity weak portion passes through the strong central portion and the weak portion again, only the photoelectric conversion element D ₂₂ outputs a substantially pulsed voltage, and the other photoelectric conversion elements are
Only the level voltage corresponding to the noise is output.

[0050] Therefore, the peak value of the photoelectric conversion element D ₂₂ E ₂₂
When compared with other peak values, the ratio (E ₁₁ /
Knowing the _{E 22, E 12 / E 22} ......), can be identified by referring to the reference particle information table, the passing position of the particle in the measurement region M 2-dimensional (Y · Z plane).

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

The flow cell 21 is made of a transparent member and has a linear flow path 21a (Y direction) of a predetermined length. Here, the cross-sectional shape of the flow cell 21 is a rectangular tube shape.
The reason for providing the linear flow path 21a having a predetermined length is the same as in the case of the flow cell 1 of the particle passage position detecting apparatus 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 the laser light La to form an irradiation area. Here, the optical axis (X direction) of the laser beam La and the linear flow path 21a (Y direction) intersect.

The condensing optical system 23 has an optical axis (X direction) that coincides with the optical axis of the laser light source 22, and has a predetermined area M (hereinafter referred to as a measurement area M) in the irradiation area shown in FIG. It has 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. They are provided adjacent to each other in the Z direction perpendicular to the (Y direction) and 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 blocks 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 is incident on the photoelectric conversion element 24.

The processing device 25 includes the peak values (pulse heights) Ea, Eb, of the voltages output by the three photoelectric conversion elements 24a, 24b, 24c while the particles pass through the measurement region M.
Peak value detecting means 26a, 26b, 26 for detecting Ec
c and position detecting means 2 for creating a particle information reference table
It consists of 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 the voltages output by the photoelectric conversion elements 24a, 24b, 24c, respectively. , 26c are used, but not necessarily the peak value, for example, the photoelectric conversion element 2
The output voltages of 4a, 24b, and 24c may be detected at the same timing, and the output voltages may be used for the subsequent arithmetic processing. Further, as the voltage detecting means, the photoelectric conversion element 24a,
The output voltages of 24b and 24c may be integrated and output for a predetermined time.

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

The operation of the particle passage position detecting device according to the third embodiment of the present invention having the above structure will be described. As shown in FIG. 12, a fluid containing particles is poured 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 region M the particle passes through.
The 4c output waveform is various. In the case of the photoelectric conversion element array 24 including the three photoelectric conversion elements 24a, 24b, and 24c, five main passage patterns can be considered.

First, when the standard particles pass through the center Mc of the measurement region M shown in FIG. 12, the spot S of the scattered light Ls by the standard particles has a photoelectric conversion element array as shown in FIG. 13 (a). It appears only in the photoelectric conversion element 24b at the center of 24, and moves in the arrow direction. At this time, the output waveform of each photoelectric conversion element 24a, 24b, 24c (relationship between time t and voltage E) is as shown in FIG. 13 (b). That is, only the photoelectric conversion element 24b outputs a substantially pulsed 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 (time t1 to time t2). However, the other photoelectric conversion elements 24a and 24c output only substantially level voltages (peak values Ea and Ec) corresponding to noise.

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

Similarly, when the standard particle passes through the other end Ms (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 particle is
As shown in FIG. 15A, it appears only in the photoelectric conversion element 24c at the other end of the photoelectric conversion element array 24, and moves in the arrow direction. At this time, each photoelectric conversion element 24a, 24b, 24
The output waveform of c (relationship between time t and voltage E) is shown in FIG.
As shown in (b). That is, only the photoelectric conversion element 24c moves the other end portion Ms of the measurement region M for a certain time (time t3
To a time t4), a substantially pulse-shaped voltage (peak value Ec) corresponding to the scattered light Ls of the standard particles is output, and the other photoelectric conversion elements 24a and 24b generate a substantially level voltage (peak value Ea) corresponding to noise. , Eb) only.

Further, when the standard particles pass through one path Mm of the measurement region M shown in FIG. 12, the spot S of the scattered light Ls by the standard particles is, as shown in FIG. 16 (a), a photoelectric conversion element. It appears across the boundary between 24a and the photoelectric conversion element 24b, and moves in the direction of the arrow. At this time, the output waveforms (relationship between time t and voltage E) of the photoelectric conversion elements 24a, 24b, 24c are as shown in FIG. 16 (b). That is, the photoelectric conversion elements 24a and 24b pass through the one path Mm of the measurement region M for a certain time (time t5 to time t6) and have a substantially pulsed voltage (peak value Ea, corresponding to the scattered light Ls of the standard particles). Eb) is output, and the photoelectric conversion element 24c outputs only a substantially level voltage (peak value Ec) corresponding to noise.

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

Then, in the position detecting means 27, FIG.
As shown in (a), when the spot S appears only in the central photoelectric conversion element 24b, 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 in the calculation unit 17a. To calculate Ea
Since <Eb, the ratio Ea / Eb is almost zero (Ea / Eb
The value of / 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 substantially zero (Ec / Eb≈0) is output as the ratio Ec / Eb and stored in the storage unit 27b.

Further, 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 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 in the calculation unit 27a. To calculate Ea
Since> Eb, a very large value (Ea / Eb≈∞) as the ratio Ea / Eb is output 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.
Since b is calculated and Ec≈Eb, a value of about 1 (Ea / Eb≈1) is output as the ratio Ea / Eb, and the storage unit 27b
Remember.

Further, 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 ratio Ea / of the peak voltage Ea of the photoelectric conversion element 24a to the peak voltage Eb of the photoelectric conversion element 24b in the calculation unit 27a. 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, the ratio Ec / Eb is a very large value (Ec / Eb≈ ∞) is output and stored in the storage unit 27b.

Next, in the position detecting means 27, as shown in FIG.
As shown in (a), when the spot S appears across the boundary between the photoelectric conversion elements 24a and 24b,
In the calculation unit 27a, 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 is calculated, and 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, and since Ec <Eb, the ratio Ec / Eb is almost zero (Ec / Eb≈0). The value of is output and stored in the storage unit 27b.

Further, the position detecting means 27 has the structure shown in FIG.
As shown in (a), when the spot S appears across 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 substantially 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. 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.

The reference voltage is the photoelectric conversion element 2
Photoelectric conversion elements 24a other than the peak voltage Eb of 4b,
The peak voltages Ea and Ec of 24c may be used, or the sum (Ea + Eb + Ec) of each peak voltage may be used. In short, it is not the absolute value of the peak voltage of the photoelectric conversion elements 24a, 24b, 24c, but the photoelectric conversion elements 24a, 2 for the reference voltage.
This is because it is more accurate to obtain the position of the spot S of the scattered light Ls by the standard particles from the ratio (ratio) of the peak voltages of 4b and 24c.

FIG. 9 shows the above five cases.
Similar to the particle information reference table shown in (1), a particle information reference table when the reference voltage is the peak voltage Eb of the photoelectric conversion element 24b can be created. 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 passage position of the particle in the measurement region M in the Z direction can be identified from among the five passage positions.

In addition to the above-mentioned five passage patterns, the measurement area M in which the spot S appears across the boundary between the photoelectric conversion element 24a and the photoelectric conversion element 24b or the boundary between the photoelectric conversion element 24b and the photoelectric conversion element 24c. Even when the photoelectric conversion element 24a passes through the path of the above, 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
Ratio E of peak voltage Ec of photoelectric conversion element 24c to b
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,
It is possible to identify the passage position of the particles in the measurement region M in the Z direction.

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

Although the flow cell has a rectangular sectional shape in the above-described embodiment of the invention, it may have a circular sectional shape.

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

[0077]

As described above, according to the invention of claim 1, the particles are not affected by the magnitude of the scattered light intensity of the passing particles due to the laser light intensity distribution of the measurement region irradiated with the laser light, and the particles are The position of the passage that has passed can be detected.

According to the second aspect of the invention, the position of the flow path through which the particles pass can be determined without being affected by the magnitude of the scattered light intensity of the passing particles due to the laser light intensity distribution in the measurement region irradiated with the laser light. Can be detected.

According to the invention of claim 3, the position of the passage through which the particles pass can be determined without being affected by the magnitude of the scattered light intensity of the passing particles accompanying the laser light intensity distribution in the measurement region 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 can be determined without being affected by the magnitude of the scattered light intensity of the passing particles associated with the laser light intensity distribution in the measurement region irradiated with the laser light. Can be detected.

According to the fifth aspect of the invention, the position of the flow path through which the particles have passed can be detected without being affected by the magnitude of the scattered light intensity of the particles associated with the laser light intensity distribution in the measurement region.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a particle passage position detection 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 vertical cross-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 in FIG. 1 and an output waveform (b) at that time.

FIG. 5 is a diagram showing a light receiving state (a) of the photoelectric conversion element array in FIG. 1 and an output waveform (b) at that time.

FIG. 6 is a diagram showing a light receiving state (a) of the photoelectric conversion element array in FIG. 1 and an output waveform (b) at that time.

7 is a diagram showing a light receiving state (a) of the photoelectric conversion element array in FIG. 1 and an output waveform (b) at that time.

FIG. 8 is a diagram showing a light receiving state (a) of the photoelectric conversion element array in FIG. 1 and an output waveform (b) at that time.

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

FIG. 10 is a configuration diagram of a particle passage position detection 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.

FIG. 12 is a vertical cross-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 in FIG. 11 and an output waveform (b) at that time.

14 is a diagram showing a light receiving state (a) of the photoelectric conversion element array in FIG. 11 and an output waveform (b) at that time.

15 is a diagram showing a light receiving state (a) of the photoelectric conversion element array in FIG. 11 and an output waveform (b) at that time.

16 is a diagram showing a light receiving state (a) of the photoelectric conversion element array in FIG. 11 and an output waveform (b) at that time.

17 is a diagram showing a light receiving state (a) of the photoelectric conversion element array in FIG. 11 and an output waveform (b) at that time.

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

[Explanation of symbols]

1, 11, 21 ... Flow cell, 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 ... Photo detecting means, 20 ... Trap.

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G01N 15/14 G01N 15/02

Claims (5)

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