JP2000074929A - Head device of dispenser - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a head device by which a reagent, a specimen or the like in an ultrasmall amount can be dropped with good accuracy as a liquid drop. SOLUTION: The head device is constituted in such a way that a chip 6 is constituted of an inside chip part 61 and an outside chip part 62 and that air is supplied from an air pump 12 to a gap between both chip parts 61, 62. As a result, a liquid, in a trace amount, which is discharged from the tip of the inside chip part 61 and which is stuck as a liquid drop is dropped by the air which is spouted from the gap.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a head device of a dispenser, and more particularly to a head device of a dispenser capable of accurately discharging a very small amount of liquid such as a reagent or a specimen.

[0002]

2. Description of the Related Art As shown in FIG. 7, a conventional dispenser has a three-axis driving mechanism 10 controlled by a controller 107.
A head device 103 for sucking and discharging a liquid such as a reagent is attached to the output section 2 downward.

On the other hand, when dispensing a reagent into each recess 91 of the plate 9 set on the dispensing table 101, the head device 103 is driven by driving the three-axis driving mechanism 102.
Is appropriately moved in the horizontal plane and the vertical plane. Then, the tip of the head device 103 approaches the concave portion 91 of the plate 9, and the reagent in the head device 103 is discharged into the concave portion 91. When diluting or mixing the reagent, the recess 9
1 is filled with another reagent in advance, and the head device 10
Injection is performed by bringing the reagent discharged from the tip of No. 3 and adhering as a droplet into contact with the liquid surface of the reagent in the concave portion 91 to release the surface tension.

[0004]

However, in such a conventional dispenser, when the head device 013 itself comes into contact with the reagent in the concave portion 91, the reagent adheres to the tip of the head device 103, and Since the attached reagent is mixed with other reagents in the next dispensing step, it is difficult to perform accurate dispensing.

When dispensing, diluting or mixing a reagent as described above, the head device 103 is lowered under the control of the controller 107 so that the tip of the head device 103 is positioned at the reagent liquid level in the concave portion 91 of the plate 9. However, since the liquid level of the reagent varies for each of the recesses 91, it is necessary to measure the liquid level of the reagent and adjust the height position of the head device 103 each time. is there. At this time, a high precision of about 0.1 mm is required for measuring the liquid level of the reagent.

[0006] In terms of the accuracy of distance measurement, it is generally known that it is advantageous to use a laser measuring instrument. In this case, however, a laser beam is applied to the reagent, so that a transparent reagent, Not applicable for reagents that cause photochemical reactions. Further, since the liquid surface has irregularities due to surface tension and the reflection direction is not uniform, there is a problem in the light receiving sensitivity of the reflected wave.

Accordingly, the present invention has been made in view of such problems, and a head device of a dispenser capable of precisely dropping a very small amount of a reagent or a specimen as a droplet is provided. To provide.

[0008]

A head device of a dispenser according to the present invention comprises a hollow nozzle, a needle inserted into the nozzle, a driving means for moving the needle in the nozzle, and a tip of the nozzle. In the head device of a dispensing machine that sucks and discharges liquid by driving the driving means and depressurizing and pressurizing the inside of the chip,
The tip includes an inner tip portion communicating with the nozzle, and an outer tip portion disposed outside the inner tip portion, and gas supply means for supplying gas to a gap between the two tip portions is provided. I do.

In such a configuration, when the inside tip is depressurized by driving the driving means after the tip of the inside tip is brought into contact with the liquid to be aspirated, the liquid is filled in the inside tip due to a pressure difference from the outside air pressure. It is sucked. In addition, when the driving means is driven to pressurize the inner chip in a state where the liquid is sucked into the inner chip portion, the liquid is discharged from the inner chip due to a pressure difference from the external air pressure, and becomes a droplet as the inner chip. It adheres to the tip of the part or is dropped. At this time, when the droplet is attached to the tip of the inner chip portion, the droplet is dropped by supplying the gas from the gas supply means from the gap between the inner chip portion and the outer chip portion.

Further, the tip of the inner tip portion is aligned with or protrudes from the tip of the outer tip portion.

With this configuration, the gas supplied from the gas supply means through the gap between the inner tip portion and the outer tip portion is jetted in the direction in which the droplets are dropped.
Then, the droplet at the tip of the inner tip portion is dropped in the direction in which the gas is ejected.

[0012] Further, a valve means is provided between the gap and the gas supply means, and a driving means is driven to pressurize the inside tip portion to form a droplet at the tip of the inside tip portion, and then the valve mechanism is opened. By ejecting gas from the gap, the droplets are ejected.

[0013] A pressure sensor for detecting a pressure in the gap is provided.

In such a configuration, when the gap between the inner tip portion and the outer tip portion approaches the liquid surface of the container to be suctioned and discharged, the gas supplied from the gas supply means becomes difficult to flow, and the pressure in the gap is reduced. Rises. Then, the liquid level is detected by detecting an increase in the pressure in the gap.

The inner tip portion and the outer tip portion include a conductive member, and an energization sensor for detecting an energization state between the two tip portions is provided. It is characterized in that the liquid level of a target container is detected.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic configuration diagram showing the entire configuration of the dispenser according to the present embodiment, FIG. 2 is a schematic configuration diagram showing the configuration of a head device of the dispenser of FIG. 1, and FIG. 3 is a head of FIG. FIG. 4 is a schematic configuration diagram showing a configuration of a chip of the apparatus, FIG. 4 is a control block diagram showing a control system of the dispenser of FIG. 1, and FIGS. 5 and 6 are flowcharts for explaining operations of the dispenser of FIG.

As shown in FIG. 1, the dispenser according to the present embodiment has a three-axis driving mechanism comprising an X-axis driving unit 21, a Y-axis driving unit 22, and a Z-axis driving unit 23 on a dispensing table 1. 2, the head device 3 is attached to the output end of the Z-axis drive mechanism 23. The three-axis driving mechanism 2 includes:
A shaft drive motor (not shown) for each of 1, 22, and 23
And each of the axis driving units can be independently moved by the axis driving motor. The control of each of the axis driving units 21, 22 and 23 is performed by the controller 7 arranged on the dispensing table 1.

An air pump 12 as a gas supply means is arranged on the dispensing table 1, and is connected to the head device 3 via an air tube 13. The air tube 13 includes an electromagnetic valve 14 and controls the amount of gas supplied from the air pump 13.

As shown in FIG. 2, the head device 3 includes a bottomed cylindrical frame 31 and a plunger 33 elastically supported on the bottom surface of the frame 31 via a spring 32.

A needle-like needle 34 projects from the lower surface of the plunger 33. The needle 34 projects toward the nozzle 4 through an opening 31a provided at the center of the bottom surface of the frame 31. The opening 31a and the needle 34
An O-ring 37 as a sealing member is interposed between the two members 31a and 34 to close a gap between the two members 31a and 34.

The screw shaft 3 is provided on the upper surface of the plunger 33.
One end of the screw shaft 6 is fixed, and the screw shaft 36 is connected to a motor 51 as driving means via a gear mechanism 52. The screw shaft 36 is threaded on its side surface, and moves the plunger 33 attached to the distal end upward or downward by rotating. A position sensor for detecting the position of the plunger is disposed on the side of the screw shaft 36, and the suction and discharge amount of the liquid is controlled based on the output of the position sensor 38.

The head device 3 has a nozzle 4 below the frame 31. The nozzle 4 includes an inner nozzle 41 and an outer nozzle portion 42 disposed outside the inner nozzle 41 at a predetermined interval. A connection port 43 for connecting the air tube 13 is provided on a side surface of the outer nozzle portion 42. Have been. Thereby, the gap 4 between the nozzle portions 41 and 42 is
4 and the air tube 13 communicate with each other.

Further, the head device 3 has a chip 6 below the nozzle 4. As shown in FIG. 3, the chip 6 includes an inner chip portion 61 and an outer chip portion 62 arranged outside the inner chip portion 61 at a predetermined interval. Is slightly shorter than the tip. The inner tip portion 61 is attached so as to cover the tip of the inner nozzle portion 41, and the outer tip portion 62 is attached so as to cover the tip of the outer nozzle portion 42. In addition, O-rings 63 and 64 are inserted as sealing members between the inner tip portion 61 and the inner nozzle portion 41 and between the outer tip portion 62 and the outer nozzle portion 42, respectively. It is closing the gap. Thus, the gap 65 between the two tip portions 61 and 62 communicates with the air pump 12 via the gap 44 between the two nozzle portions and the air tube 13.

Next, a control system of the dispenser according to the present embodiment will be described.

The control system of the dispenser according to this embodiment is as follows.
As shown in FIG. 4, the controller 7 is mainly configured.

The controller 7 includes a main controller 70 for controlling the whole, a three-axis controller 71 for controlling the three-axis driving mechanism 2, a head controller 72 for controlling the motor 39 in the head device 3, and opening and closing of the solenoid valve 14. And a valve opening / closing controller 73 for controlling

The main controller 70 inputs and outputs information necessary for dispensing from a personal computer 75 via a communication interface 74, and a communication interface 76.
, Information from the pressure sensor 15 and the position sensor 38 is input.

The three-axis controller 71 receives a three-axis driver 77 based on a control signal from the main controller 70.
X-axis drive motor 21M, Y-axis drive motor 22M
And the drive of the Z-axis drive motor 23M. The control signal is generated by the main controller 70 based on the information on the target position input from the personal computer 75 and the information on the current position of the head device 3.

The head controller 72 controls the driving of the motor 51 via a motor driver 78 based on a control signal from the main controller 70. The control signal includes a suction amount and a discharge amount input from the personal computer 75,
This is generated by the main controller 70 based on the output of the position sensor 38 and the output of the pressure sensor 15.

The valve opening / closing controller 73 controls opening / closing of the electromagnetic valve 14 via a valve opening / closing driver 79 based on a control signal from the main controller 70. This control signal is generated by the main controller 70 based on the outputs of the position sensor 38 and the pressure sensor 15.

Next, the suction and discharge operations of the dispenser having the above-described configuration will be described with reference to FIGS.

When sucking the liquid contained in the container 92 into the tip 6 of the dispenser, first, as shown in FIG. 5, the air pump 12 is driven and the electromagnetic valve 14 is opened. (Step S01) Thereafter, based on a control signal supplied from the main controller 70 to the three-axis driver 77 via the three-axis controller 71, the X-axis drive motor 21M and the Y-axis drive motor 2
2M is driven to move the head device 3 above the container 92. (Step S02) Next, the Z-axis drive motor 23M is driven to lower the head device 3, and the tip of the chip 6 is immersed in the liquid stored in the container 92. At this time, since the solenoid valve 14 is in the open state and air is supplied from the air pump 12 to the gap 65 of the chip 6 via the air tube 13,
When the head device 3 is further lowered after the front end of the first chip portion reaches the liquid surface, and the front end of the outer chip portion 62 reaches the liquid surface, the gap 65 between the two chip portions 61 and 62 is closed. Pressure rises. The pressure in the gap 65 is measured by the pressure sensor 15 and is compared with a predetermined threshold by the main controller 70. As a result, the pressure sensor 15
The output of the main controller 70
Determines that the tip of the chip 6 has reached the liquid level, and sends a control signal to the three-axis controller 71 and the valve opening / closing controller 73 so as to stop the Z-axis drive motor 23M and close the solenoid valve 14. Output. (Step S0
3 to S05) The main controller 70 outputs a control signal to the motor driver 78 via the head controller 72 so as to suck the liquid stored in the container 92.
In response to this, when the motor 51 is driven, the rotation is transmitted to the screw shaft 36 via the gear mechanism 52, and the plunger 33 moves upward. When the needle 34 rises with the rise of the plunger 33, the pressure in the inner tip portion 61 sealed by the needle 34 and the liquid level decreases, and the liquid in the inner tip portion 61 due to a pressure difference from the outside air pressure. Is sucked. At this time, the moving plunger 3
The position 3 is detected by the position sensor 38, and according to the output of the position sensor 38 and the amount of liquid to be sucked,
The rotation of the motor 51 is controlled. (Step S06) Next, when the suction of a predetermined amount of liquid from the container 92 is completed,
When the solenoid valve 14 is opened for a few seconds after the head device 3 is raised to a position sufficiently distant from the liquid surface, undesired liquid that has entered the gap 65 of the chip 6 due to capillary action during suction is discharged from the air pump 12. It is returned into the container 92 by the supplied air. Thus, the liquid suction operation ends. (Steps S07 and S08) Next, in a case where the liquid contained in another container is sucked while the liquid is being sucked, the head device 3 is moved above the container to be sucked, and the steps S01 to S08 described above are performed. By performing the operation, a similar suction operation can be performed.
At this time, even if the head device 3 is in a state of sucking the liquid, the pressure in the gap 65 is detected by the pressure sensor 15, so that the liquid level can be detected based on the output. It has become. (Step S09) In addition, when the liquid is discharged to a container containing another liquid while the liquid is being sucked, as shown in FIG.
X-axis drive motor 21M and Y-axis drive motor 22M based on a control signal supplied to 3-axis driver 77 through
Is driven to move the head device 3 above the container.
(Steps S10, S11) Next, the Z-axis drive motor 23M is driven to lower the head device 3 to a predetermined height. This height is set to such a height that the tip of the chip 6 does not contact the liquid surface of the liquid stored in the container 92. (Step S12) After stopping the Z-axis driving motor 23M, the main controller 70 outputs a control signal to the motor driver 78 via the head controller 72 so as to discharge the liquid stored in the container 92. I do. In response,
When the motor 51 is driven, its rotation is transmitted to the screw shaft 36 via the gear mechanism 52, and the plunger 33 moves downward. When the needle 34 descends with the plunger 33 descending, the pressure in the inner tip portion 61 sealed by the needle 34 and the suctioned liquid increases, and the liquid is displaced by the pressure difference from the outside air pressure. 61
Discharged from the tip. At this time, since a small amount of liquid is ejected, the liquid adheres to the tip of the inner chip portion 61 as a droplet. Here, when the closed electromagnetic valve 14 is opened, the liquid droplets adhering to the tip of the inner tip portion 61 are dropped downward by the air blown out from the gap 65.

The amount of liquid discharged from the inner tip portion 61 is controlled in accordance with the amount of liquid to be discharged and the output of the position sensor 38 as in the case of suction. (Step S1
3, S14) Finally, the head device 3 is raised, the air pump 11 is stopped, and the ejection operation ends. (Step S
15, S16) As described above, according to the present embodiment, the tip 6 is formed of the inner tip portion 61 and the outer tip portion 62, and the air pump 1 is provided in the gap 65 between the tip portions 61 and 62.
2 is supplied, a small amount of liquid discharged from the tip of the inner tip portion 61 and attached as a droplet is dropped by the air blown out from the gap 65. This makes it possible to precisely drop a very small amount of a reagent or a specimen as a droplet.

Further, since the tip of the outer tip portion 62 is the same as or shorter than the tip of the inner tip portion 61, droplets adhering to the tip of the inner tip portion 61 are prevented from flowing from the gap 65. Air can be blown effectively.

Instead of discharging the liquid from the inner chip portion 61 with the electromagnetic valve 14 opened, the liquid is discharged from the inner chip portion 61, and then the electromagnetic valve 14 is opened to drop liquid droplets. , It is possible to drop the liquid as large droplets as possible, and it is possible to drop the liquid with higher precision.

Further, since the pressure sensor 15 for detecting the pressure in the gap 65 is provided, the liquid surface of the liquid contained in the container 92 to be suctioned and discharged is sucked into the inner tip portion 61. It is possible to detect whether or not the state is set.

In the present embodiment, an automatic dispenser that controls the three-axis drive mechanism 2 by the controller 7 is used as a dispenser, but a portable dispenser that operates the head device 3 by hand. Can be used for dispensers.

In this embodiment, the pressure sensor 15 detects the level of the liquid contained in the container 92. However, both the inner tip portion 61 and the outer tip portion 62 are made of a conductive material. And liquid level detection can be performed. In this case, both tip portions 6
One end of each of the first and second terminals 62 is electrically connected, and an energization sensor such as a current sensor or a voltage sensor for detecting the energization state is provided. When the tips of both tip portions 61 and 62 reach the liquid surface, a change in current or voltage occurs. This is detected by an energization sensor and liquid level detection is performed.

[0040]

According to the present invention, the chip is constituted by the inner chip portion and the outer chip portion, and the gas is supplied from the gas supply means to the gap between the two chip portions. A small amount of liquid ejected from the tip of the tip portion and attached as droplets is dropped by gas ejected from the gap. This makes it possible to precisely drop a very small amount of a reagent or a specimen as a droplet.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating a configuration of an entire dispenser according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram illustrating a configuration of a head device in the dispenser of FIG.

FIG. 3 is a schematic configuration diagram illustrating a configuration of a chip in the head device of FIG. 2;

FIG. 4 is a block diagram showing a control system of the dispenser of FIG.

FIG. 5 is a flowchart showing a suction operation of the dispenser of FIG. 1;

FIG. 6 is a flowchart showing a discharge operation of the dispenser of FIG. 1;

FIG. 7 is a schematic configuration diagram showing a configuration of a conventional dispenser.

[Explanation of symbols]

 1: dispensing table 12: air pump 2: three-axis drive mechanism 3: head device 34: needle 36: screw shaft 4: nozzle 41: inner nozzle portion 42: outer nozzle portion 51: motor 6: chip 61: inner chip portion 62 : Outer tip 65: Gap 7: Controller

Continued on the front page F-term (reference) 2G058 CA01 EA02 EA04 EA11 EB05 EB08 EB15 ED02 ED07 ED12 ED13 GB03 GB04 GB10 4F033 QA05 QB02Y QB12Y QB17 QC04 QD11 QE09 QF21X QF21Y QK02Q QKXQ QQXQ

Claims (5)

[Claims] 1. A nozzle comprising: a hollow nozzle; a needle inserted into the nozzle; driving means for moving the needle within the nozzle; and a tip disposed at the tip of the nozzle. A head device of a dispenser that drives and depressurizes and pressurizes the inside of the chip to suck and discharge a liquid, wherein the chip has an inner chip portion communicating with the nozzle,
A head device for a dispenser, comprising: an outer tip portion disposed outside the inner tip portion; and gas supply means for supplying gas to a gap between the two tip portions. 2. The head device of a dispenser according to claim 1, wherein the tip of the inner tip portion is aligned with or protrudes from the tip of the outer tip portion. 3. A valve is provided between the gap and the gas supply means, and the driving means is driven to pressurize the inside tip, thereby forming a droplet at the tip of the inside tip. The head device for a dispenser according to claim 1 or 2, wherein the droplet is dropped by opening the valve mechanism and ejecting gas from the gap. 4. The apparatus according to claim 1, further comprising a pressure sensor for detecting a pressure in the gap, and detecting a liquid level of a container to be sucked and discharged based on an output of the pressure sensor. Or the head device of the dispenser according to 2. 5. An inner chip portion and an outer chip portion each including a conductive member, and an energization sensor for detecting an energization state between the two chip portions is provided, and a liquid is sucked based on an output of the energization sensor. 3. The dispenser head device according to claim 1, wherein the liquid level of a container to be discharged is detected.