JP3849953B2 - Automatic alignment mechanism of particle size distribution analyzer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a particle size distribution measuring apparatus in which scattered light obtained by irradiating a sample with light from a light source is detected by a photodetector and the particle size distribution in the sample is measured based on the scattered light intensity pattern. The present invention relates to an automatic alignment mechanism.
[0002]
[Prior art]
The configuration of the scattering type particle size distribution measuring apparatus is shown in FIG. 9, for example, in which the symbol a is a laser tube that generates laser light b, c is a beam expander that expands the laser light into a parallel beam, d is a cell containing the sample e, f is a condensing lens arranged behind the cell d, g is a photodetector comprising a photodiode for detecting scattered light emitted from the condensing lens f, and h is A multiplexer that takes in a signal from the light detector g, i is a CPU that receives the signal from the multiplexer h and performs a calculation based on the scattered light intensity pattern to obtain a particle size distribution.
[0003]
In such a particle size distribution measuring apparatus, the optical axes of the laser tube a and the light detector g must coincide with each other with high precision. However, the laser tube a is subject to thermal distortion, cell d, condenser lens f, light When the bench (not shown) provided with the detector g or the like is distorted by heat, or when the cell d is replaced, the optical axis may be displaced due to a change in the mounting position. The optical axis is adjusted every degree.
[0004]
For this purpose, although not shown in the figure, a four-part optical axis adjustment light-receiving unit made of a photodiode is provided at the center of the optical axis of the photodetector g, and the four light-receiving components constituting the optical axis adjustment light-receiving unit are provided. Optical axis alignment was performed prior to measurement by moving the photodetector g in the XY axis directions so that the magnitudes of the intensity signals output from the elements were equal.
[0005]
[Problems to be solved by the invention]
In order to move the above-described photodetector g in the XY axis direction, normally, as shown in FIG. 9, two actuators m and n such as a piezoelectric element and a stepping motor are used, and the photodetector g is A light receiving element made up of a plurality of photodiodes formed in an arc shape so as to be called a ring detector is arranged in a fan shape on the plate surface to form a large plate. Therefore, in order to secure the amount of movement (or the number of steps) required for adjusting the optical axis, a relatively large space is required in the apparatus, and the configuration is complicated.
[0006]
The present invention has been made in view of such circumstances, and provides an automatic alignment mechanism of a particle size distribution measuring apparatus that has a simple and compact configuration that can automatically adjust an optical axis without moving a photodetector. It is aimed.
[0007]
[Means for Solving the Problems]
In the present invention, means for solving the above-described problems are configured as follows.
That is, in the first aspect of the present invention, the light source, the first lens system, the second lens system for condensing the light beam, and the photodetector are provided, and the light is emitted by irradiating the sample. An auto alignment mechanism of a scattering type particle size distribution measuring apparatus for measuring a particle size distribution of a sample on the basis of a scattered light intensity pattern obtained by detecting scattered light with the light detector, wherein the light detector A check pattern as a measurement unit for detecting transmitted light for adjusting the optical axis is provided on the light receiving surface, and the light source is swung in the XY-axis direction with respect to the light receiving surface of the photodetector. a pair of actuators for manipulating the direction in which the tip made of a spherical mutually orthogonal to each other, is opposed to the pair of actuator spring disposed back, further, the XY-axis direction of the base of the light source as the center Together with the base portion is supported by the support member so as to be swingable, while the distal end portion of the light source is sandwiched between the return spring and the distal end portion of said pair of actuators, were pre-set and stored According to the optical axis adjustment program, based on the detection signal from the check pattern, the light source is oscillated to adjust the optical axis so that the received light intensities of the plurality of light receiving elements of the check pattern are all equal. An optical axis adjustment processing unit for sending a control signal to the actuator is provided.
[0008]
The invention according to claim 2 includes a light source, a first lens system, a second lens system for condensing a light beam, and a photodetector, and scattered light generated by irradiating the sample with light. Is an auto-alignment mechanism of a scattering-type particle size distribution measuring apparatus that measures the particle size distribution of a sample based on a scattered light intensity pattern obtained by detecting the light by the light detector. A check pattern as a measurement unit for detecting transmitted light for adjusting the optical axis is provided on the surface, and the light source is connected to the first lens system or the first lens system and the second lens system. A pair of actuators for integrating the light source and the first lens system or the first lens system and the second lens system with respect to the light receiving surface of the photodetector in the XY axis direction are spherical. consisting of the tip each other Provided in a direction mutually perpendicular to the spring provided back to face the pair of actuators, further, said light source and said first lens system or, in a fixed state of the first lens system and the second lens system to the case body The one end side of the case body is supported by a support member, and the other end side of the case body is swingable in the XY axis direction so that the other end side of the case body is the tip of the pair of actuators. In accordance with an optical axis adjustment program set and stored in advance, all received light intensities of the plurality of light receiving elements of the check pattern are all based on detection signals from the check pattern. An optical axis adjustment processing unit is provided that sends a control signal for swinging the light source and the lens system to the actuator to adjust the optical axes to be equal. It is characterized in that it comprises.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of an auto-alignment mechanism of a scattering type particle size distribution apparatus of the present invention will be described in detail below with reference to the drawings.
FIG. 1 shows the configuration of the apparatus. Reference numeral 1 is a light source (laser tube) for generating laser light, and 2 is a beam expander (first lens system referred to in the present invention) that appropriately expands the laser light into a parallel beam. Thus, for example, it consists of two convex lenses 21 and 22 (see FIG. 4A). The light source 1 is supported by the support member 3 so as to be swingable in the XY-axis direction in a plane perpendicular to the paper surface with the base as a center, and the tip portions made of spherical surfaces are orthogonal to each other. A pair of actuators 4, 5 provided in a matching direction and return springs 41, 51 (not shown) provided facing these actuators 4, 5 are supported, and the optical axis 11 is moved to the XY axis by swinging the light source 1. The movement can be adjusted in the direction (see FIG. 2).
[0010]
The actuators 4 and 5 are composed of, for example, step motors, and the operating shaft linked to the rotating shaft advances and retreats by the rotation thereof. As described above, the tip end portion of the spherical surface of the operating shaft and the return portion are returned. The light source 1 can be swung by sandwiching the tip of the light source 1 between the springs 41 and 51, but a piezoresistive element (PZT) may be used instead of the sputter motor.
[0011]
6 is a flow cell, 7 is a condensing lens (second lens system in the present invention) made of a convex lens, and 9 is a photodetector (see FIG. 3) in which light receiving elements made of photodiodes are arranged. transmitted light detection measurement unit for adjusting the optical axis (check pattern) 91 and, by one of the detection plane scattered light detection measurement section 9 2 provided (light receiving surface) including the transmitted light detecting measuring unit 91 Li Cheng . Reference numeral 10 denotes a multiplexer that takes in a detection signal from the light detector 9, and reference numeral 12 denotes a CPU. The signal from the multiplexer 10 is input, and the granularity is determined based on the scattered light intensity pattern according to a predetermined control program that is set and stored in advance. In addition to measuring the distribution, an optical axis adjustment processing unit for sending a control signal to the actuators 4 and 5 to adjust the optical axis 11 prior to the measurement is included.
[0012]
With such a configuration, when the sample in the flow cell 6 is irradiated with laser light, part of the laser light irradiates particles in the sample to become scattered light, and the remaining light passes between the particles. Both are transmitted light and reach the photodetector 9 together.
[0013]
In the particle size distribution measuring apparatus having such a configuration, in a state where a sample to be measured is injected into the flow cell 6 prior to measurement, first, auto alignment (automatic optical axis adjustment) is performed according to a command from the optical axis adjustment processing unit. Is done. That is, a control signal is sent to both actuators 4 and 5 so that the light receiving intensities of the four light receiving elements 911 to 914 of the transmitted light detecting measurement unit 91 are all equal, and the light source 1 receives light from the light detector 9. The optical axis 11 is automatically adjusted by swinging in the XY axis direction with respect to the surface (see FIG. 2).
[0014]
In this case, the configuration from the first lens system 2 to the bulky photodetector 9 is fixed, and the light source 1 having a relatively small size and shape may be slightly swung, and extra space is required. In addition, since the adjustment amount of the optical axis 11 can be increased by a slight swing of the light source 1, auto-alignment can be performed more quickly than in the past, and the apparatus can be made compact.
[0015]
After the above-described auto alignment is completed, the particle size distribution is measured by the measurement unit 92 for detecting scattered light. As shown in FIG. 3, the scattered light detection measuring unit 92 is configured by arranging a plurality of light receiving element arrays 92 (921 to 925) formed in an arc shape in a fan shape.
[0016]
In the present invention, the arrangement of the light receiving elements in the photodetector 9 is not limited to that shown in FIG. 3, and at least the check pattern and the scattered light detection measuring unit are formed in an appropriate arrangement of the light receiving elements on the light receiving surface. It only has to be done.
[0017]
On the other hand, the position of the above-described flow cell 6 is not limited to the position shown in FIG. 1 and may be disposed between the condenser lens 7 and the photodetector 9. Moreover, the combination of the lenses of the first lens system 2 constituting the beam expander may be appropriately selected from the combinations shown in FIGS. 4A to 4C and FIGS. 5A to 5C, for example. . 4A shows a combination of convex lenses 21 and 22, FIG. 4B shows a concave lens 23 and a convex lens 24, FIG. 4C shows a concave lens 23 and a combined lens (concave lens 24 and convex lens 25), and FIG. (A) is convex lenses 26 and 27, FIG. 5 (B) is a matched lens (convex lens 26 and concave lens 23), (concave lens 24 and convex lens 25), FIG. 5 (C) is a matched lens (convex lens 26 and concave lens 23), This is a combination of (concave lens 24 and convex lens 25).
[0018]
6 and 7 show different embodiments. In this case, the light source 1 and the first lens system 2 are integrated, and the first lens system 2, the flow cell 6 and the condenser lens 7 are fixed in the case body 8. And a tip end portion made of a spherical surface of a pair of actuators 4 and 5 provided such that one end side of the case body 8 is swingably supported by the support member 3 and the other end side is provided in a direction perpendicular to each other. The case body 8 is supported by return springs 41 and 51 (not shown), and the other end side of the case body 8 can be swung in the XY axis direction in a plane perpendicular to the paper surface. Even with such a configuration, the automatic adjustment of the optical axis 11 can be quickly completed without moving the bulky photodetector 9, and the apparatus can be made compact. Also in this case, the flow cell 6 may be provided between the condenser lens 7 and the photodetector 9.
[0019]
FIG. 8 shows another embodiment, in which case the first lens system 2 integrated with the light source 1 and the condensing lens 7 are housed in a fixed state in the case body 8, and the flow cell 6 has the case body 8. The light source 1, the first lens system 2, and the condenser lens 7 are integrally swung in the XY axis directions by the actuators 4 and 5. Automatic adjustment is possible.
[0020]
Even in this case, the automatic adjustment can be performed quickly, and the apparatus can be compactly formed. Although not shown, the first lens system 2 integrated with the light source 1 may be housed in a fixed state in the case body 8, and the light source 1 and the first lens system 2 may be swung. .
[0021]
【The invention's effect】
As described above, in the present invention, the light source, the first lens system, the second lens system for condensing the light beam, and the photodetector, and the scattering generated by irradiating the sample with light. An auto-alignment mechanism of a scattering-type particle size distribution measuring apparatus configured to measure a particle size distribution of a sample based on a scattered light intensity pattern obtained by detecting light with the light detector. The light receiving surface is provided with a check pattern as a measurement unit for detecting transmitted light for adjusting the optical axis, which includes a plurality of light receiving elements, and the light source is operated to swing in the XY axis direction with respect to the light receiving surface of the photodetector. a pair of actuators for the direction in which the tip made of a spherical mutually orthogonal to each other, is opposed to the pair of actuator spring disposed back, further, the XY-axis direction about the base of the light source Together with the base portion is supported by the support member so as to be freely moving, whereas the tip of the light source is sandwiched between the tip and the return spring of the pair of actuators, the optical axis is preliminarily set and stored In accordance with an adjustment program, based on a detection signal from the check pattern, the light source is oscillated to adjust the optical axis so that the light receiving intensities of the plurality of light receiving elements of the check pattern are all equal. By providing an optical axis adjustment processing unit that sends control signals to the actuator, it is possible to adjust the optical axis more quickly by reducing the drive amount of the actuator, making the device configuration simple and compact. It becomes.
In the present invention, the light source, the first lens system, the second lens system for condensing the light beam, and the photodetector are provided, and the scattered light generated by irradiating the sample with the light is the light. An auto-alignment mechanism of a scattering-type particle size distribution measuring apparatus that measures a particle size distribution of a sample based on a scattered light intensity pattern obtained by detecting with a detector, on the light receiving surface of the light detector, A check pattern is provided as a transmitted light detecting measurement unit for adjusting the optical axis, and includes a plurality of light receiving elements, and the light source is integrated with the first lens system or the first lens system and the second lens system. A tip of a spherical surface that is a pair of actuators for swinging the light source and the first lens system or the first lens system and the second lens system in the XY-axis direction with respect to the light receiving surface of the photodetector. part is orthogonal to each other Fit provided in a direction, are opposed to the pair of actuator spring disposed back, further, the light source and the first lens system, or housed in a fixed state of the first lens system and the second lens system to the case body, The one end side of the case body is supported by a support member, and the other end side of the case body is swingable in the XY axis direction so that the other end side of the case body is the tip of the pair of actuators and the return spring. In accordance with an optical axis adjustment program set and stored in advance, the received light intensities of the plurality of light receiving elements of the check pattern are all equal based on detection signals from the check pattern. Providing an optical axis adjustment processing unit for sending a control signal for swinging the light source and the lens system to the actuator to adjust the optical axis. Ri, quickly becomes possible to adjust the optical axis, the configuration of the device becomes as simple, it becomes possible compactness.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing an embodiment of an automatic alignment mechanism of a particle size distribution measuring apparatus of the present invention.
FIG. 2 is an explanatory diagram when adjusting the optical axis.
FIG. 3 is a front view showing an example of an array of light receiving elements of the photodetector.
4A to 4C are diagrams showing examples of lens combinations of the first lens system. FIG.
FIGS. 5A to 5C are drawings showing examples of lens combinations of the first lens system. FIGS.
FIG. 6 is a block diagram showing the same different embodiment.
FIG. 7 is an explanatory diagram when adjusting the optical axis.
FIG. 8 is a configuration diagram showing another embodiment.
FIG. 9 is a block diagram showing an example of a conventional particle size distribution measuring apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Light source, 2 ... 1st lens system, 3 ... Support member, 4, 5 ... Actuator, 7 ... 2nd lens system, 9 ... Photodetector, 91 ... Check pattern, 11 ... Optical axis, 12 ... Optical axis adjustment Processing part (CPU), 41 , 51 ... return spring, 911-914 ... light receiving element.

Claims (2)

A light source, a first lens system, a second lens system for condensing a light beam, and a photodetector, and detecting the scattered light generated by irradiating the sample with light. An auto-alignment mechanism of a scattering-type particle size distribution measuring apparatus that measures a particle size distribution of a sample based on a scattered light intensity pattern obtained by the method, comprising a plurality of light receiving elements on a light receiving surface of the photodetector A check pattern is provided as a transmitted light detection measurement unit for adjusting the optical axis, and a pair of actuators for swinging the light source in the XY-axis direction with respect to the light receiving surface of the photodetector is a spherical surface. provided in a direction in which the tip mutually orthogonal to each other, is opposed to the pair of actuator spring disposed back, further, the base in the XY-axis direction about the base of the light source so as to be swingable is supported While being supported by the member, while the distal end portion of the light source is sandwiched between the tip and the return spring of the pair of actuators, in accordance with the optical axis adjustment program was previously set and stored, detecting from the check pattern An optical axis that sends a control signal for swinging the light source to the actuator so as to adjust the optical axis so that the received light intensities of the plurality of light receiving elements of the check pattern are all equal based on the signal An auto-alignment mechanism of a particle size distribution measuring apparatus, comprising an adjustment processing unit. A light source, a first lens system, a second lens system for condensing a light beam, and a photodetector, and detecting scattered light generated by irradiating a sample with light by the photodetector. An auto-alignment mechanism of a scattering-type particle size distribution measuring apparatus that measures a particle size distribution of a sample based on a scattered light intensity pattern obtained by the method, comprising a plurality of light receiving elements on a light receiving surface of the photodetector And a check pattern as a measurement unit for detecting transmitted light for adjusting the optical axis, and integrating the light source with the first lens system or the first lens system and the second lens system . lens system, or, the distal end comprising a pair of actuators for swung to the XY-axis direction by a spherical surface is mutually orthogonal to each other the first lens system and the second lens system with respect to the light-receiving surface of the photodetector provided in a direction, The spring is provided back to face the these pair of actuators, further the light source and the first lens system, or, the first lens system and the second lens system accommodated in a fixed state to the case body, said case body It is supported at one end side supporting member, between the other end of the case body so as to be swung to the other end of the case body in the XY-axis direction between the tip and the return spring of the pair of actuators one sandwiched accordance optical axis adjustment program was previously set and stored, based on the detection signal from the check pattern, the so each received light intensity is equal for all of the plurality of light receiving elements of the check pattern light A particle size comprising an optical axis adjustment processing section for sending a control signal for swinging the light source and the lens system to adjust the axis to the actuator. Automatic alignment mechanism of cloth measuring device.

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