JPS6314768B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a counting device for extremely small objects, and particularly to a counting device that can easily count microscopic objects existing as insoluble substances in a liquid under high-speed conditions.

Conventionally, the typical method for counting microscopic objects in liquid is to use the diffraction phenomenon of ultrasonic waves, but this method is difficult to correct for the type, shape, and size of the detected object, and the equipment is difficult to correct. It had the disadvantage of being very expensive, so it was not widely used.

On the other hand, the method of observing objects with a diameter of about 20 μm using a stereomicroscope is generally adopted as the simplest method, but since this method relies on the observer's vision and intuition, many It required time and effort, was not suitable for regular work, and had problems with counting accuracy.

To solve this problem, Japanese Patent Application Laid-Open No. 1973
In Japanese Patent Publication No. 95884, a structure of an ivy particle analyzer with real-time analysis capability was proposed, and in Japanese Patent Application Laid-Open No. 54-24683, a coefficient method for fine particles in liquid was proposed, which is in the same technical field as the present invention. Proposed.

However, the former invention is of a type in which a liquid feeding line, which is a combination of a pump and a valve, is connected to a sample passage tube containing a sample chamber (corresponding to the flow cell of the present invention) to forcefully feed the sample. Since the pumps and valves inevitably come into contact with the sample liquid, contamination is unavoidable.Therefore, the pumps and valves must be cleaned after every measurement, which is disadvantageous and requires a lot of labor and lost time.

On the other hand, the latter invention has a structure in which a sample passage tube having a quantitative storage part is connected in a hanging state to the bottom of a sample container in which a sample liquid is stored in advance, and the sample passage tube is The measurement procedure is complicated because it is necessary to wash the sample liquid in the sample container or to perform the measurement after draining the required amount of sample liquid from the sample container. The Kotoku method also has the same problem as the former invention because it is contaminated by the sample liquid.

Moreover, what these conventional devices have in common is that they have unresolved problems in that they are difficult to handle because the ease of operation during measurement is not one-sided but is multi-faceted.

In order to cope with these circumstances, the present invention is a scientific method that can solve the various problems of the conventional method while fully utilizing the characteristics of a counting means using laser light, which is highly directional and has excellent measurement accuracy. It was designed to provide a rational device, and in particular, it has a sample buffer section 21, a sample charge section 20, and a flow cell 2 arranged one above the other in order and communicates with each other. A sample passage tube 13 is formed by connecting air bleed tubes to the sample buffer section 21 in a variety of ways, and allows the sample liquid 1 filled up to the sample buffer section 21 to flow down at a fixed rate in a vertical direction, and the flow tube 13 serves as a detection section. A laser oscillator 3 and a projection magnifying section 4 are provided on both the left and right sides of the device body with the cell 2 in between.
and at least one reflecting mirror 8, 10, 11 that refracts the laser beam, and a lens 9 that magnifies the laser beam after passing through the flow cell 2, and projects the laser beam onto the flow cell 2 and targets the target object. The projection magnifying section 4 has an optical means for magnifying and imaging the flow state of the flowing liquid in the flow cell 2 on the projection magnifying section 4, and has a light receiving area corresponding to its magnification magnification and the size of the maximum object to be counted. A plurality of photoelectric conversion elements 5 are arranged in parallel so as to be able to cross the fluid flow surface of the effective portion of the enlarged projected image.
and an arithmetic and counting section for calculating and counting changes in the electrical signals of the photoelectric conversion elements 5 and counting the ultrafine particles in the sample liquid 1 as relative values, forming a counting device for ultrafine objects in the liquid. Therefore, regardless of the type or shape of the object to be detected, it is easy to select the size of the object, and it can be counted simply and quickly, and the cost of the equipment is also low.
Since the valves in each air supply line do not come into contact with the sample liquid, only the sample passage tube 13 is required for cleaning before and after measurement, streamlining the measurement work.Moreover, the measurement work can be simplified by front operation. It has been reached.

The specific contents of the device of the present invention will be explained in detail below with reference to the accompanying drawings.

Figures 1 and 2 are diagrams for explaining the basic principles of the device, in which a fixed amount of sample liquid 1 is passed through the flow cell 2 at a constant speed in the vertical direction (in the direction penetrating the paper in Figure 1). ), a laser beam L emitted from a laser oscillator 3 is transmitted through the flow cell 2 to form an enlarged image of the flowing state of the flowing liquid in the flow cell 2 on the projection magnifying section 4. A group of photoelectric conversion elements 5 provided in the projection magnifying section 4 and a monitor screen 6 detect the state of the flowing liquid in a photoelectric conversion manner and in an image manner, thereby receiving electrical signals from the group of photoelectric conversion elements. While the counting unit counts the minute objects, the monitor screen monitors the minute objects with images magnified several dozen times.

Here, the photoelectric conversion element group and the monitor screen 6
As schematically shown in FIG. 2, in the illustrated example, a plurality of photoelectric conversion elements 5, for example, a group of phototransistors, are arranged closely in a straight line on the projection magnifying section 4, and a monitor screen 6 is placed on top. The group of photo transistors is
A total of 36 transistors are arranged in a 100mm space with a pitch of 2.78mm, and a highly directional phototransistor with a lens with a light-receiving surface of 1.346mmφ detects the brightness and darkness signals from the image of the microscopic object in the sample liquid, and sends it to the calculation and counting section. It is set up so that it can be conveyed.

As an example, the laser oscillator 3 is a He--Ne gas laser oscillator, which emits red monochromatic light (wavelength
0.6328μ and a beam diameter of 1.2φ, this light beam is reflected by the total reflection mirror 8 and projected onto the flow cell 2 when the shutter 7 is open, and the transmitted light passes through the lens 9 and the total reflection mirrors 10 and 11. The flow state of the sample liquid 1 flowing through the flow cell 2 is imaged on this portion.

In FIG. 2, one photoelectric conversion element 12 provided directly above a group of photoelectric conversion elements 5 is for verifying the illuminance of the laser beam.

As clarified by the above explanation, the basic structure of the apparatus of the present invention includes a sample distribution line including the flow cell 2, and a laser beam projected onto the flow cell 2 to flow the flowing liquid in the cell 2. An optical means for forming an image of the state on the projection magnifying section 4, and a fluid flow in the effective portion of the enlarged projection image of the projection magnifying section 4, each having a light-receiving area according to its magnification and the size of the maximum object to be counted. A plurality of photoelectric conversion elements 5 arranged in parallel so as to be able to cross the lower surface, and a calculation and counting section for calculating and counting changes in electrical signals of the photoelectric conversion elements 5 and counting ultrafine particles in the sample liquid 1 as relative values. The projection magnifying section 4 is further provided with a monitor section 6 as required.

The shape of the main body of this device is as shown in FIGS. 3 and 4, respectively, as shown in FIG. 3 and FIG. The flow cell 2 located at an intermediate position is held vertically by a support stand 14, while the optical means includes laser oscillators 3 on both sides of the central part of the main body where the sample passage tube 13 is provided.
A monitor screen 6, a focusing handle 15, a center adjustment micrometer 16 (see Fig. 6), etc. are arranged in a front-facing position, and the entire unit can be operated from the front. It has a possible horizontal structure.

Next, structural examples of each main part will be explained one by one with reference to FIG. 5 and subsequent figures.

Figure 5 shows an overview of the sample distribution line.
A glass tube 18 inserted into a sample container 25 filled with a sample liquid 1 is connected to a lower tube opening of a flow cell 2 via a ball joint 19, and further has a sample charge section 20 and a sample buffer section 21 in communication with each other. , and a transparent glass conduit having phototube switches 22, 23, 24 interposed in the upper and lower parts of both parts 20, 21 is connected to the upper tube opening of the flow cell 2 to form the sample passage tube 13. be done.

This sample passage tube 13 includes a steady measurement tube having a solenoid valve 26 and a needle valve 27, a bleed tube having a solenoid valve 28 and connected to a vacuum pump 29, and a monitoring tube having a needle valve 30. Connected in many ways.

In the flow cell 2, four pieces of glass (material: Vycor) are sufficiently polished to minimize distortion, and a sample flow part with a rectangular cross section (20 mm x 1 mm) is formed in the center. Although it may have a circular cross section, it is preferable to have a rectangular cross section from the perspective of the projection magnifying section 4.

The usage of the sample distribution line configured as described above is as follows.

When the electromagnetic valve 28 is opened, the sample liquid 1 in the sample container 25 flows upward through the glass tube 18 and the flow cell 2 under the bleed action of the vacuum tank 29, and then sequentially flows upward through the sample charge section 20 and the sample buffer section 21. When the sample liquid level crosses the phototube switch 24, the solenoid valve 28 is activated by a command from the switch 24.
to close.

Thereafter, when the electromagnetic valve 26 is opened with the needle valve 27 slightly open to supply air to the sample passage tube 13, the sample liquid 1 filling the tube 13 flows down at a slow speed. However, the sample liquid level gradually falls, and when the sample liquid level passes through the sample buffer section 21 and crosses the phototube switch 23, the arithmetic and counting section is activated by a command from the switch 23.

In this way, the sample filling step before starting the actual measurement is completed, but if you wish to monitor the flow state of the sample liquid 1 in advance using the monitor screen 6 of the projection magnifying section 4, the solenoid valve 26 should be closed. needle valve 30
The sample liquid 1 may be allowed to flow down at a slower speed until the liquid level passes through the phototube switch 23 by slightly opening the phototube switch 23.

In addition, by providing the sample buffer section 21, the initial liquid phase when flowing upward flows into the flow cell 2.
It is possible to eliminate the inconvenience that measurement errors are likely to occur when the actual measurement is carried out as the liquid flows down to This is extremely advantageous because it makes it possible to eliminate undesirable phenomena such as contamination or leakage.

After the above steps are completed, the solenoid valve 26 is opened to allow one sample liquid to flow downward for the actual measurement.
This solenoid valve 26 is opened when the liquid level is the photocell switch 23.
It continues until it descends from the point where it passes through the phototube switch 22.

In this way, the volumes of the sample passage tube 13 and the sample charging section 20 that exist between both switches 22 and 23 are fixed, and the velocity of the flowing liquid is constant according to the opening degree of the needle valve 27, so that quantitative and constant Needless to say, rapid measurement becomes possible.

The support base 14 for vertically holding the flow cell 2 has a center adjustment mechanism shown in FIG.
The focusing mechanism shown in FIG. 7 allows fine adjustment movements left and right, front and back, and the optical axis of the flow cell 2 is aligned with respect to the laser beam that crosses the flow cell 2 by operating the micrometer 16. is carried out, and
By operating the handle 15, the lens 9 (see FIG. 4) is brought into focus via a rotational linear motion conversion mechanism 17 consisting of a pinion rack.

On the other hand, the illuminance verification circuit for detecting the illuminance of laser light in the optical system is shown in FIG.
The electrical signal generated by the photoelectric conversion element 12 upon reception of light is amplified by an OP amplifier (OP ₁ ) and then can be confirmed by a meter M.

Therefore, by adjusting the output of the laser oscillator 3 while observing the indication on the meter M, it is possible to easily set the appropriate illuminance.

Next, an outline of the arithmetic and counting section provided in relation to a group of photoelectric conversion elements 5 will be explained with reference to FIGS. 9 to 11.
1, amplifier 32, comparator 33, one shot multi circuit 34, IC circuit 35, adder circuit 36,
It consists of a counter 37 and a display 38, and the functions of each component are as follows.

Signals from each photoelectric conversion element, that is, each sensor 5n, are passed through a high-pass filter 31 to remove low frequency components such as sensor drift components, dark current, and changes in light source illumination, so that stable counting can be performed.

Next, the amplifier 32 amplifies the signal and adjusts the gain to equalize variations in sensor sensitivity, and then the comparator 33 sets a threshold value that determines the minimum size of ultrafine particles to be counted. Determine.

Comparator 3 is activated due to the detection of insoluble matter.
After removing illegal counts from the digital signals generated in step 3 using a one-shot multivibrator, each piece of information from the 36 sensors 5 is added up in an adding circuit 36 and displayed on a display 38 via a counting circuit 37. let

Next, the measurement means performed using the above-mentioned apparatus will be explained.

The sample liquid 1 in the sample container 25 is sucked up into the sample passage tube 13 in the manner described above, and when the liquid level reaches the position of the phototube switch 24, the solenoid valve 28 is closed, and this state is maintained or the needle valve 30 is closed. After opening and monitoring as necessary, turn on the laser oscillator 3 and turn on the focusing handle 1.
5. After adjusting the focus and optical axis by operating the center adjustment micrometer 16 and adjusting the illuminance of the laser beam, the liquid starts flowing down by opening the solenoid valve 26. Then, when the liquid level passes the position of the phototube switch 23, the arithmetic and counting unit starts counting, and stops counting when the liquid level passes the position of the phototube switch 22.

During this time, the liquid flow state within the flow cell 2 is imaged on the projection magnifying section 4 by the transmission of the laser beam L.

The image of the microscopic object is represented as a dark spot, and the image of the other solution is represented as a bright visual field, and the dark spots are counted when they pass through the photoelectric conversion elements 5.

Here, the microscopic object passes through an arbitrary position in the cross section of the flow cell 2, but since a group of photoelectric conversion elements 5 are arranged transversely to the projection magnification section 4 corresponding to the cross section of the flow cell 2, , it can always be detected by either one of them.

Furthermore, the size of the fine particles determines their image formation, that is, the size of the dark spot, and therefore, the size of the light blocking surface for the photoelectric conversion element can change as the fine particles pass through.

That is, as larger particles pass through, the change in the detection signal becomes larger, so by appropriately adjusting the level of the comparator 33 in the arithmetic and counting section, the lower limit of the size of the microscopic object to be detected can be arbitrarily set. Furthermore, the monitor screen 6 is extremely effective in focusing the position and image to be detected.

Note that laser light is monochromatic light with a single wavelength,
Light interference occurs when passing through the flow cell 2, which tends to cause moiré in the image, resulting in several intermittent changing signals for one particle, which causes errors in measured values. It is possible that

In response to this, the one-shot multi-circuit 34 provided in the arithmetic and counting section functions to eliminate incorrect counts based on the moiré phenomenon, thus making it possible to perform accurate measurements.

When cleaning the sample passage tube after counting is finished or for replacing with another sample liquid, replace the sample liquid in the sample container 25 with the cleaning liquid and repeat the rising and falling flow. Cleaning can be done easily and quickly just by doing this.

As detailed above, the device of the present invention has a structure that allows the sample liquid to flow at a constant rate and at a constant rate.
Since the counting accuracy is high and the counting is performed automatically, there is no variation in measurement, and measurement can be carried out at high speeds, resulting in a significant improvement in work efficiency.

Furthermore, since a laser beam is used as the light source, reliable imaging can be obtained due to the highly directional light source, and the measurement accuracy is far superior to those using conventional iodine bulbs and mercury bulbs. It is truly worth noting that a device has emerged that allows product manufacturers to conduct quality evaluations accurately and quickly.

The present invention also provides a sample buffer section 21 to carry out the main measurement by causing the sucked up sample liquid 1 to flow down after passing through the sample charge section 20. Measurement accuracy can be improved by not using the liquid phase for measurement, and additional equipment such as the solenoid valve for steady measurements and the needle valve of the solenoid valve for filling the sample does not come into contact with the sample liquid. It has the advantage of not being contaminated at all.

Furthermore, the present invention has the practical advantage of being front-operated and easy to handle.

[Brief explanation of the drawing]

Each figure shows an aspect of an example of the device of the present invention, with FIG. 1 being a basic principle explanatory diagram, FIG. 2 being a schematic structural diagram of a projection magnifying section, FIG. 3 being an external perspective view, and FIG. 4 not showing main parts. Plan view, Figure 5 is a schematic structural diagram of the sample distribution line, Figures 6 and 7 are side and front views showing the main structure, Figure 8 is a laser beam illuminance verification circuit diagram, and Figure 9 is a calculation diagram. The block diagram of the counting section, FIGS. 10 and 11, are electrical circuit diagrams of the main parts in FIG. DESCRIPTION OF SYMBOLS 1... Sample liquid, 2... Flow cell, 3... Laser oscillator, 4... Projection enlarger, 5... Photoelectric conversion element, 6... Monitor screen, 8, 10, 11... Reflection mirror, 9...
Lens, 13...Sample passage tube, 20...Sample charge section, 21...Sample buffer section, 22, 23, 24...
Phototube switch, 34...one-shot multi-circuit.

Claims (1)

[Claims] 1 A sample buffer section 21, a sample charge section 20, and a flow cell 2 are arranged vertically in this order and communicated with each other, and a steady measurement tube and an air bleed tube are connected to the sample buffer section 21 in various ways. A sample passage tube 13 for allowing the sample liquid 1 filled up to the buffer section 21 to flow down at a constant speed in a vertical direction.
, a laser oscillator 3 and a projection magnifying section 4 provided on both left and right sides of the apparatus main body, sandwiching the flow cell 2 as a detection section, and at least one reflecting mirror 8, 10, 11 that refracts the laser beam. A lens 9 for magnifying the laser beam after passing through the flow cell 2 is provided, and an optical system for projecting the laser beam onto the flow cell 2 and forming an enlarged image of the flowing state of the flowing liquid in the flow cell 2 on the projection magnifying section 4. and a plurality of photoelectrons having a light-receiving area according to the magnification and the size of the maximum object to be counted and arranged in parallel so as to be able to cross the fluid flow surface of the enlarged projection image effective portion of the projection enlarger 4. Ultrafine particles in a liquid comprising a conversion element 5 and a calculation/counting section for calculating and counting changes in the electrical signals of the photoelectric conversion elements 5 and counting the ultrafine particles in the sample liquid 1 as relative values. Small object counting device.