Dispensing system

Abstract

Provided is a dispensing system capable of dispensing a liquid from a pipette tip in an amount smaller than one drop by using an articulated robot.　This dispensing system comprises: a first container that contains a liquid to be dispensed; a second container 3 into which the liquid to be dispensed 9 is dispensed; a dispensing nozzle 5 to which a pipette tip 4 for aspirating the liquid to be dispensed is attached; a pump that performs the action of exerting pressure for aspirating and discharging the liquid on the dispensing nozzle 5; an articulated robot that holds the dispensing nozzle 5 and moves so as to perform a plurality of tasks; and a control device that controls the operation of the pump and the operation of the articulated robot. The control device performs, as a micro amount discharging task for discharging a micro amount of the liquid to be dispensed from the pipette tip 4 to the second container 3, a task for moving the dispensing nozzle 5 through the articulated robot so that a tip end port 44 of the pipette tip 4 touches an inner wall 31a of the second container 3 once and separates therefrom after the pipette tip 4 that has aspirated the liquid to be dispensed is tilted from an upright orientation to an angled orientation.

Description

Dispensing System

[0001] The present invention relates to a dispensing system for dispensing a liquid.

[0002] 2. Description of the Related Art Conventionally, a technique for dispensing a predetermined amount of liquid into a container is known, for example, from Japanese Patent No. 6610127 (Patent Document 1).

[0003] Patent Document 1 describes a dispensing device that includes a dispensing unit having a pipe and a pump for aspirating and dispensing a liquid, a washing unit that washes the dispensing unit with a washing liquid, a container for a liquid to be dispensed that contains an organic solvent as a main component, a washing container for a washing liquid, a dispensing container into which the liquid to be dispensed is dispensed, and a control unit that controls the operation of the dispensing unit and the washing unit. Patent Document 1 also describes that the control unit operates the dispensing unit and the washing unit so that after the washing liquid is aspirated into the pipe of the dispensing unit, the liquid to be dispensed is further aspirated across a gas, the liquid to be dispensed aspirated into the pipe is discharged into the dispensing container, and the liquid to be dispensed and the washing liquid remaining in the pipe are discarded, and the pipe is washed with the washing liquid.

[0004] Patent No. 6610127 (Claim 1, Figures 1-3)

[0005] The present invention provides a dispensing system that can dispense a liquid to be dispensed from a pipette tip in an amount less than one drop using an articulated robot.

[0006] a pump that applies pressure to the dispensing nozzle to suck in and discharge liquid; an articulated robot that holds the dispensing nozzle and moves to perform a plurality of tasks; and a control device that controls the operation of the pump and the articulated robot, wherein the control device performs a micro-dispensing operation of dispensing a micro-amount of liquid from the pipette tip into the second container by causing the articulated robot to move the dispensing nozzle so that the pipette tip that has sucked in the liquid to be dispensed is tilted from an upright position, and then the tip of the pipette tip touches and then releases the inner wall of the second container.

[0007] According to the first aspect of the present invention, the liquid to be dispensed can be dispensed from the pipette tip in an amount less than one drop using an articulated robot.

[0008] 11(A) is a perspective view of a dispensing system according to an embodiment of the present invention. FIG. 11(A) is a plan view of the dispensing system of FIG. 1. FIG. 11(B) is a side view of a dispensing nozzle and a pipette tip. FIG. 11(B) is a functional block diagram showing the configuration of a control system in the dispensing system. FIG. 11(B) is a flowchart showing a part of a dispensing operation by the dispensing system. FIG. 11(B) is a flowchart showing the remaining part of the dispensing operation of FIG. 5. FIG. 11(B) is a flowchart showing the re-aspiration operation in the dispensing operation of FIG. 6. FIG. 11(B) is a flowchart showing the micro-dispensing operation in the dispensing operation of FIG. 6. FIG. 11(B) is a perspective view showing a state in which a first container is placed on a first weighing machine and a second container is placed on a second weighing machine. FIG. 11(B) is a perspective view showing a state in which a pipette tip is attached to a dispensing nozzle held by a robot arm. FIG. 11(B) is a side view showing a state in which a pipette tip has been moved above a first container. FIG. 11(B) is a side view showing a state in which a tip of the pipette tip of FIG. 11(A) is inserted into a first container. FIG. 11(B) is a side view showing a state in which a pipette tip has been moved above a second container. FIG. 11(B) is a side view showing a state in which a pipette tip to be dispensed is being placed in an upright position. 14(A) is a side view showing a state in which the pipette tip is held in an upright position above the second container before micro-dispensing. 14(B) is a side view showing a state in which the pipette tip of FIG. 13(A) is in a tilted position. 14(C) is a side view showing a state in which the pipette tip in a tilted position has been moved so as to approach the inner wall of the second container. 14(A) is a side view showing a state in which the pipette tip of FIG. 14(A) has been moved so that its tip opening touches the inner wall of the second container. 14(B) is an explanatory diagram showing a state in which the liquid to be dispensed protrudes from the tip opening of the pipette tip and stops. 14(A) is an explanatory diagram showing a state in which the tip opening of the pipette tip and the liquid to be dispensed exposed from the tip opening have been moved so as to touch the inner wall of the second container. 14(B) is an explanatory diagram showing a state in which the pipette tip of FIG. 15(A) has been moved so as to move away from the inner wall of the second container. 14(C) is an explanatory diagram showing a state in which only the tip opening of the pipette tip has been moved so as to touch the inner wall of the second container. 14(B) is an explanatory diagram showing an example of a tilted position of the pipette tip.

[0009] Hereinafter, an embodiment of the present invention will be described.

[0010] (Configuration of Dispensing System) Figures 1 and 2 show a dispensing system 1 according to an embodiment of the present invention. As shown in Figures 1 and 2, the dispensing system 1 according to this embodiment includes a first container 2, a second container 3, a first weighing device 25, a second weighing device 35, a dispensing nozzle 5 to which a pipette tip 4 is attached, a pump 6, an articulated robot 7, a control device 8, etc.

[0011] 1 and the like, reference numeral 10 denotes a workbench. The workbench 10 includes, for example, a box-shaped main body 10a having a top plate 10b. If necessary, the workbench 10 may be provided with a cover or the like that encloses and covers the space above the top plate 10b.

[0012] The dispensing system 1 basically uses an articulated robot 7 to dispense a predetermined amount of a dispensing target liquid 9 contained in a first container 2 into a second container 3. More specifically, the dispensing system 1 is configured to perform the dispensing operation via a pipette tip 4 attached to a dispensing nozzle 5 that is held by the articulated robot 7 and connected to a pump 6.

[0013] The dispensing target liquid 9 is a liquid that is to be dispensed. The dispensing target liquid 9 used in the dispensing system 1 is a type of liquid that requires dispensing in an accurate amount, in other words, dispensing with relatively high precision. The dispensing target liquid 9 is also a liquid that has a viscosity that allows it to be dripped in granular form from the tip opening of the pipette tip 4. Examples of the dispensing target liquid 9 include liquids used in pharmaceuticals and other chemicals, chemical products containing organic solvents, reagents, fragrances, pigments, water, beverages, and the like.

[0014] The first container 2 is a container that contains the dispensing target liquid 9 that is to be dispensed. As shown in Fig. 1 , the first container 2 has at least a main body 21 that contains the dispensing target liquid 9 and an opening 22 for inserting and removing the dispensing target liquid 9. Although only one first container 2 is shown in Fig. 1 , in reality, as many first containers 2 as are necessary for the dispensing operation are prepared. When preparing multiple first containers 2 to perform the dispensing operation, for example, the multiple first containers 2 may be arranged side by side on a placement table 24 that is installed on the top plate 10b of the workbench 10, as illustrated by the two-dot chain line in Fig. 2 .

[0015] The size and shape of the main body 21 of the first container 2 are not particularly limited, as long as it can accommodate the required amount of the liquid to be dispensed 9. The size and shape of the opening 22 of the first container 2 are not particularly limited, as long as it is possible to insert at least the tip of the pipette tip 4 therein and perform the operation of aspirating the liquid to be dispensed 9. Furthermore, it is preferable that the opening 22 be closed with a lid (not shown) when handling, such as putting in and taking out the liquid to be dispensed 9, is not required. When the opening 22 of the first container 2 is opened and closed with a lid during dispensing, the lid opening and closing operation may be configured to be performed automatically, for example, by using a dedicated articulated robot, lid opening and closing device, or the like that performs the lid opening and closing operation and the container moving and setting operation.

[0016] The second container 3 is a container that contains the target liquid 9 to be dispensed. As shown in FIG. 1 , the second container 3 has at least a main body 31 that contains the target liquid 9 and an opening 32 for inserting and removing the target liquid 9. Although only one second container 3 is shown in FIG. 1 , in reality, as many second containers 3 as necessary for the dispensing operation are prepared. When multiple second containers 3 are prepared for dispensing, similar to the case of the first container 2, the multiple second containers 3 may be arranged side by side on a placement table 34 installed on the top plate 10b of the workbench 10, as illustrated by the two-dot chain line in FIG. 2 . Furthermore, the second containers 3 may contain a predetermined liquid before dispensing the target liquid 9. In this case, if the liquid contained in the second containers 3 is different from the target liquid 9, the dispensing operation using the dispensing system 1 also serves as a blending operation.

[0017] There are no particular restrictions on the size and shape of the main body 31 of the second container 3, as long as it is capable of containing the amount of the dispensing target liquid 9 to be dispensed. There are no particular restrictions on the size and shape of the opening 32 of the second container 3, as long as it is possible to dispense the dispensing target liquid 9 using the pipette tip 4. It is also preferable that the opening 32 be closed with a lid (not shown) when handling, such as putting in and taking out the dispensing target liquid 9, is not required.

[0018] The first weighing device 25 is a weighing device that weighs the weight of the dispensing target liquid 9 contained in the first container 2. The second weighing device 35 is a weighing device that weighs the weight of the dispensing target liquid 9 contained in the second container 3 by dispensing. The first weighing device 25 and the second weighing device 35 may be, for example, an electronic balance. The first weighing device 25 and the second weighing device 35 are installed at predetermined positions on the workbench 10.

[0019] As shown in Fig. 1, the first weighing device 25 in this embodiment has a weighing pan 26 on which an object to be weighed is placed, and is used with the first container 2 placed on the weighing pan 26. Also, as shown in Fig. 1, the second weighing device 35 has a weighing pan 36 on which an object to be weighed is placed, and is used with the second container 3 placed on the weighing pan 36. As shown in Fig. 1, the first weighing device 25 and the second weighing device 35 in this embodiment are installed in the lower space of the installation base 12 fixed on the workbench 10, and are installed in a state where the weighing pans 26, 36 are exposed from two openings (not shown) provided in the top plate of the installation base 12.

[0020] The first weighing device 25 is used after being adjusted, for example, by zero resetting, so as to measure the weight obtained by subtracting the weight of the empty first container 2, i.e., the weight of only the liquid to be dispensed 9 contained in the first container 2. The second weighing device 35 is used after being adjusted so as to measure the weight obtained by subtracting the weight of the empty second container 3, i.e., the weight of only the liquid to be dispensed 9 contained in the second container 3.

[0021] Furthermore, in this embodiment, as shown in Figures 1 and 2, a positioning device 13 is provided in each of the first weighing device 25 and the second weighing device 35. The positioning device 13 is a device that sandwiches and positions the first container 2 to be placed on the weighing pan 26 of the first weighing device 25 and the second container 3 to be placed on the weighing pan 36 of the second weighing device 35 at specific positions on the weighing pans 26, 36, respectively, to align them. Centering is performed when aligning them at the center positions of the weighing pans 26, 36.

[0022] The positioning device 13 in this embodiment is composed of a first clamping device 14 that clamps and positions the body 21 of the first container 2 placed on the weighing pan 26 from the outside, and a second clamping device 15 that clamps and positions the body 31 of the second container 3 placed on the weighing pan 36 from the outside. As shown in Figure 2, the first clamping device 14 has a pair of grippers 14a, 14b that move open and close parallel to the horizontal direction. In addition, the second clamping device 15 has a pair of grippers 15a, 15b that move open and close parallel to the horizontal direction.

[0023] 3 and other figures, the pipette tip 4 is a cylindrical tool that can suck in and hold the liquid 9 to be dispensed inside the tip side and dispense it. The pipette tip 4 is composed of, for example, a substantially cylindrical main body 41, a tapered portion 42 formed in a tapered shape at the end that becomes the tip of the main body 41, and an attachment portion 43 formed at the end of the main body 41 opposite the tapered portion 42. A tip opening 44 is provided at the tip of the tapered portion 42.

[0024] The pipette tip 4 in this embodiment is detachably attached to the dispensing nozzle 5 for use. Various capacities of the pipette tip 4 are possible, for example, capacities ranging from 5 to 10 ml (milliliters). In this embodiment, a pipette tip 4 with a capacity of 10 ml is used, taking into consideration the combination of dispensing a relatively large amount of liquid in addition to dispensing a minute amount of liquid, as described below. The 10 ml capacity pipette tip 4 has a tip opening 44 with an outer diameter of approximately 3 mm and an inner diameter of approximately 1.5 to 2.5 mm.

[0025] Furthermore, when the liquids 9 to be dispensed are different types, the pipette tips 4 are used so as to be disposable after each dispensing operation. Therefore, multiple pipette tips 4 are prepared for each dispensing operation. In this embodiment, as shown in FIG. 1 and other figures, multiple pipette tips 4 are stored in a storage rack 46. The multiple pipette tips 4 are stored in the storage rack 46 with their mounting portions 43 facing upward, in an orderly arrangement, and in a state where they can be easily removed. Furthermore, when the liquids 9 to be dispensed are the same type and multiple dispensing operations are performed using the same liquid 9 to multiple second containers 3, the same pipette tips 4 can be used consecutively. In this case, when multiple pipette tips 4 need to be used, the multiple pipette tips 4 can be stored in the storage rack 46. The pipette tips 4 are placed in predetermined positions on the workbench 10 by the storage rack 46.

[0026] 3 and other figures, the dispensing nozzle 5 is a tubular device to which a pipette tip 4 is attached and which causes the pipette tip 4 to suck up and dispense a liquid 9 to be dispensed. In this embodiment, the dispensing nozzle 5 is composed of, for example, a main body 51, an attached portion 52, a gripped portion 53, and a tubing attachment portion 54. The dispensing nozzle 5 is also formed with a passage 55 that penetrates the main body 51, the attached portion 52, the gripped portion 53, and the tubing attachment portion 54.

[0027] The main body 51 is a cylindrical portion that extends elongatedly in a straight line. The mounting portion 52 is a portion to which the pipette tip 4 is attached and is formed at the lower end of the main body 51. As shown by the dashed line in FIG. 3 , the mounting portion 52 is fitted into the mounting portion 43 of the pipette tip 4 (see FIG. 16(B) ), enabling the pipette tip 4 to be attached. The gripped portion 53 is a portion to be gripped by a hand unit 75 (described later) of the articulated robot 7 and is formed at the end of the main body 51 opposite the mounting portion 52. The gripped portion 53 is configured as, for example, a disk-shaped structure, and a groove 53a for gripping is formed on the side of the disk. The piping attachment portion 54 is a portion to which a piping 65 connecting to the pump 6 is attached and is formed at the upper end of the main body 51.

[0028] As shown in FIG. 1 and other figures, when not in use, the dispensing nozzle 5 in this embodiment is placed on a holding stand 56 that is installed in a predetermined position on the workbench 10. The holding stand 56 is a structure in which a holding portion 57 (see FIG. 10) is provided at the upper end of a support. The support is installed in a predetermined position on the top plate 10b of the workbench 10. The holding portion 57 is a portion in which a recess is formed that holds the entire dispensing nozzle 5 by detachably inserting the lower part of the gripped portion 53 of the dispensing nozzle 5. The holding stand 56 is configured so that when held by the holding portion 57, the attached portion 52 of the dispensing nozzle 5 is kept floating and separated from the top plate 10b of the workbench 10.

[0029] The pump 6 is a device that exerts pressure on the dispensing nozzle 5 to draw in and discharge liquid. The pressure is obtained by moving and stopping air. The pump 6 is preferably a pump that can finely adjust the amount of the liquid 9 to be dispensed drawn in and discharged from the dispensing nozzle 5 and, ultimately, the pipette tip 4 attached to the dispensing nozzle 5. The pump 6 is connected to the pipe fitting 54 of the dispensing nozzle 5 by a pipe 65. The pipe 65 is a flexible tube, and a portion of the pipe 65 is suspended from above by a hanging fixture (not shown) so as not to interfere with the movement of the articulated robot 7.

[0030] In this embodiment, a syringe pump is used as the pump 6. The syringe pump is capable of controlling the amount of the liquid 9 to be dispensed to, for example, about 0.01 ml in order to properly perform the micro-dispensing operation described below. The syringe pump is also configured to drive the movement of the syringe piston with a servo motor in order to achieve high-precision control. While this embodiment illustrates an example in which the pump 6 is installed on the top plate 10b of the workbench 10, the installation location is not particularly limited.

[0031] The articulated robot 7 is a robot that moves to hold at least the dispensing nozzle 5 and perform a plurality of tasks, such as attaching the pipette tip 4, aspirating the liquid 9 to be dispensed, and dispensing the liquid 9 to be dispensed. The plurality of tasks will be described in detail later in the description of the dispensing operation, etc. The articulated robot 7 has an articulated arm 72 and a hand 75 that is attached to the tip of the arm 72 and performs the tasks.

[0032] As shown in Figure 1, the articulated robot 7 in this embodiment uses an arm unit 72 having six-axis joints that moves on a base 71, and uses a gripper device 76 that grasps the dispensing nozzle 5 as the hand unit 75.

[0033] 2, the gripper device 76 includes a main body 76a attached to the tip of the arm 72, and a pair of grippers 76b, 76c that open and close in parallel on the main body 76a so as to sandwich the gripped portion 53 of the dispensing nozzle 5 from the outside. In addition, by rotating a part of the arm 72, for example, the main body 76a of the gripper device 76 can be rotated together with the pair of grippers 76b, 76c to a required angle.

[0034] The control device 8 is a device that controls the operation of various devices that make up the dispensing system 1, such as the pump 6 and the articulated robot 7. The control device 8 is disposed, for example, inside an operation table 18 that is installed next to the work table 10, as shown in FIG. 1 etc. An operation panel 19 that operates the dispensing system 1 is provided on the top surface of the operation table 18. The control device 8 may be installed in a location separate from the dispensing system 1. When installed in a separate location, the control device 8 remotely controls the operation of the dispensing system 1.

[0035] As shown in FIG. 4, the control device 8 includes a central control unit 81, a robot control unit 82, a pump control unit 83, and a positioning and clamping control unit 84.

[0036] The central control unit 81 is a control unit that comprehensively controls the overall operation of the dispensing system 1. The central control unit 81 has a processing unit 811 that processes various types of information, and a storage unit 812 that stores information such as control programs and various data. The central control unit 81 is configured from a hardware perspective of an arithmetic processing unit, a storage element, an input / output device, etc. The robot control unit 82 is also configured from a hardware perspective of almost the same as that of the central control unit 81. The robot control unit 82, pump control unit 83, and positioning and clamping control unit 84 are connected to the central control unit 81 in a manner that allows information to be communicated. The first weigher 25, second weigher 35, and operation panel 19 are also connected to the central control unit 81 in a similar manner.

[0037] The robot control unit 82 is a control unit that controls the operation of the articulated robot 7. The robot control unit 82 has a processing unit 821 that processes various types of information, etc. The robot control unit 82 is connected to the arm drive unit 73 of the arm unit 72 and the hand drive unit 78 of the hand unit 75 to be controlled in a manner that allows information to be communicated. The arm drive unit 73 and the hand drive unit 78 are parts that drive the power source of the arm unit 72 and the power source of the hand unit 75, respectively, and are composed of components such as motors and sensors. Information such as the range of motion for various tasks that is set in advance and the position of an object whose position is fixed is input into the robot control unit 82 in advance. Details of control related to operations for various tasks will be described later.

[0038] The pump control unit 83 is a control unit that controls the operation of the pump 6. The pump control unit 83 has a processing unit 831 that processes various types of information, etc. The pump control unit 83 is connected to the pump drive unit 63 of the pump 6 to be controlled in a form that allows information to be communicated. The pump drive unit 63 is a part that drives the power source of the pump, and is composed of parts such as a motor and a sensor.

[0039] Information such as operation details for various preset operations is input in advance to the pump control unit 83. Examples of the various preset operations include a suction operation for suctioning the dispensing target liquid 9 and a discharge operation for dispensing the dispensing target liquid 9. The pump control unit 83 also controls the operation using information on the weighing results of the first weigher 25 and the second weigher 35. Details of the control of the operation of the pump 6 will be described later.

[0040] The positioning and clamping control unit 84 is a control unit that controls the operations of the first clamping device 14 and the second clamping device 15 in the positioning device 13. The positioning and clamping control unit 84 is connected to the gripper drive unit 141 of the first clamping device 14 and the gripper drive unit 151 of the second clamping device 15, which are the objects to be controlled, in a form that allows information to be communicated. The gripper drive units 141, 151 are parts that drive the power sources of the first clamping device 14 and the second clamping device 15, respectively, and are composed of components such as motors and sensors. The positioning and clamping control unit 84 controls the opening and closing operations of the grippers 14a, 14b of the first clamping device 14 and the grippers 15a, 15b of the second clamping device 15 at predetermined times during the dispensing operation.

[0041] The pump control unit 83 and the positioning and clamping control unit 84 are configured as part of the functions of the processing unit 811 of the central control unit 81. However, the pump control unit 83 and the positioning and clamping control unit 84 may also be configured as control units independent of the central control unit 81.

[0042] The operation panel 19 is a section for performing operations necessary to operate the dispensing system 1. The operation panel 19 is equipped with an input section 191, an output section 192, etc. Of these, the input section 191 is a section for processing information obtained from an input device 19a (FIG. 2) into which the operator of the dispensing system 1 inputs operation information necessary for operating the device. Furthermore, the output section 192 is a section for processing information display on a display device 19b (FIG. 2) that displays information such as setting conditions, setting contents, and status necessary for operating the dispensing system 1.

[0043] The input device 19a may be a switch, button, or liquid crystal display panel that can be used for input operations. The display device 19b may be a lamp, liquid crystal display panel, or the like. Such an operation panel 19 is installed in a location that is easy for the operator of the dispensing system 1. The operation panel 19 is provided in a part of the operation table 18, for example, as shown in FIG. 1 etc.

[0044] 1 and other drawings, the dispensing system 1 is also provided with a tip disposal unit 16 that removes and discards used pipette tips 4 from the dispensing nozzle 5. The tip disposal unit 16 is provided, for example, in a predetermined location on the workbench 10. In this embodiment, the tip disposal unit 16 is composed of a disposal port provided in a predetermined location on the top plate 10b of the workbench 10, a tip hook (not shown) provided midway along the disposal port for hooking the pipette tip 4, and a waste storage box (not shown) installed below the disposal port (in the space below the top plate 10b). The tip hook is, for example, a portion formed with an insertion recess that is narrower than the maximum diameter portion of the pipette tip 4 and wider than the outer diameter of the dispensing nozzle 5.

[0045] (Operation of Dispensing System) Next, the operation of dispensing by the dispensing system 1 will be described.

[0046] The dispensing system 1 operates to automatically perform dispensing operations in principle, except for some operations that are performed manually. In the dispensing system 1 described below, the above-mentioned 10 ml pipette tip 4 is used, and a syringe pump is used as the pump 6.

[0047] First, in the dispensing system 1, the operator performs the following manual pre-dispensing tasks before performing automatic dispensing.

[0048] That is, as shown in Figure 9, the operator places the first container 2 containing the liquid to be dispensed 9 on the weighing pan 26 of the first weigher 25, and places the empty second container 3 on the weighing pan 36 of the second weigher 35. The operator also performs a preparatory operation of storing the required number of unused pipette tips 4 in the storage rack 46. Furthermore, the operator performs an input operation using the input device 19a of the operation panel 19 to input necessary information such as the type of liquid to be dispensed 9, the target weight to be dispensed, etc. Here, the second container 3 may be one that already contains a liquid different from the liquid to be dispensed 9. If the second container 3 already contains a different liquid, the dispensing system 1 will perform a blending operation simultaneously with the dispensing operation.

[0049] Next, after completing these pre-dispensing operations, the operator operates the operation panel 19 to start the dispensing system 1 .

[0050] At this time, information input to the input unit 191 from the input device 19a of the operation panel 19 during the pre-dispensing work is transmitted to the central control unit 81 of the control device 8. In addition, necessary information from the input information is also transmitted from the central control unit 81 to the robot control unit 82 and the pump control unit 83.

[0051] 9, in the first weighing machine 25, the first clamping device 14 in the positioning device 13 is activated and the pair of grippers 14a, 14b close to clamp the body 21 of the first container 2, thereby positioning the first container 2 at the reference position on the weighing dish 26. Meanwhile, in the second weighing machine 35, the second clamping device 15 in the positioning device 13 is activated and the pair of grippers 15a, 15b close to clamp the body 31 of the second container 3, thereby positioning the second container 3 at the reference position on the weighing dish 36.

[0052] Furthermore, at this time, the first weighing device 25 weighs the weight of the liquid to be dispensed 9 contained in the first container 2, and the measurement result is sent to the control device 8. At this time, the weight of the first container 2 is deducted in advance and treated as non-existent. Also, the second weighing device 35 weighs the weight of the second container 3, but this weight is deducted in advance and treated as non-existent.

[0053] 5 and 6 show the flow of the main operations in the dispensing operation by the dispensing system 1. In Fig. 5, step S101 shows the operation of placing a first container on a first weighing machine, and step S102 shows the operation of placing a second container on a second weighing machine. In this embodiment, the operations of steps S101 and S102 are configured to be performed manually.

[0054] (Preparation for automated dispensing operation) Then, in the dispensing system 1, when the automatic dispensing operation is started, as shown in Figures 5 and 10, the articulated robot 7 starts under the control of the control device 8 and causes the hand portion 75 to grasp the dispensing nozzle 5 (step S103).

[0055] At this time, the articulated robot 7 moves the arm 72 under control of the robot control unit 82, and moves the hand unit 75 closer to the holding stand 56 of the dispensing nozzle 5. Thereafter, the articulated robot 7 activates the gripper device 76 of the arm 72 to clamp and grip the gripped portion 53 of the dispensing nozzle 5 with the grippers 76b and 76c (see FIG. 9), and removes the dispensing nozzle 5 from the holding portion 57 of the holding stand 56 (see FIG. 10).

[0056] Next, in the dispensing system 1, as shown in FIGS. 5 and 10, the articulated robot 7 is actuated to attach the pipette tip 4 to the dispensing nozzle 5 held by the hand unit 75 (step S104).

[0057] At this time, the articulated robot 7 moves the arm 72 to move the hand unit 75 in an upright position so that it approaches the storage rack 46 of the pipette tips 4. Thereafter, the articulated robot 7 moves the arm 72 to lower the dispensing nozzle 5 held by the hand unit 75 toward one of the pipette tips 4 in the storage rack 46, and also fits the mounting portion 52 of the dispensing nozzle 5 into the mounting portion 43 of the pipette tip 4 by a predetermined amount to mount it (see FIG. 3 ).

[0058] In addition, in the dispensing system 1, when the first container 2 is placed on the weighing pan 26 of the first weigher 25 and the second container 3 is placed on the weighing pan 36 of the second weigher 35, the first clamping device 14 and the second clamping device 15 are activated under the control of the positioning clamping control unit 84 of the control device 8, and the positioning of the first container 2 and the positioning of the second container 3 are performed, respectively.

[0059] Specifically, the first clamping device 14 moves the grippers 14a and 14b to lightly clamp the first container 2 horizontally from the outside, thereby positioning the first container 2 at a predetermined position (e.g., the center position) on the weighing tray 26 of the first weigher 25. The second clamping device 15 moves the grippers 15a and 15b to lightly clamp the second container 3 horizontally, thereby positioning the first container 2 at a predetermined position (e.g., the center position) on the weighing tray 36 of the second weigher 35. Immediately after positioning, the first clamping device 14 opens the grippers 14a and 14b to release the clamping of the first container 2. Immediately after positioning, the second clamping device 15 also opens the grippers 15a and 15b to release the clamping of the second container 3.

[0060] (Operation of aspirating the liquid to be dispensed) Next, in the dispensing system 1, as shown in Figures 5 and 10, the articulated robot 7 is operated under the control of the robot control unit 82 of the control device 8, and moves the pipette tip 4 attached to the dispensing nozzle 5 to the first container 2, and then inserts the tip of the pipette tip 4 into the first container 2 (step S105).

[0061] At this time, the articulated robot 7 moves the arm 72 to move the hand 75 so that it is above the first container 2 placed on the first weigher 25 (see FIG. 11(A)). Next, the articulated robot 7 moves the arm 72 to lower the pipette tip 4, which is attached to the dispensing nozzle 5 and held in a substantially vertical position, toward the first container 2 and into the main body 21 through the opening 22 of the first container 2. Finally, the articulated robot 7 moves the arm 72 to insert the distal end opening 44 of the pipette tip 4 a predetermined distance into the main body 21 of the first container 2 so that it is immersed in the liquid 9 to be dispensed (see FIG. 11(B)).

[0062] In the dispensing system 1, for example, a height position Hp of the liquid level 9s of the liquid to be dispensed corresponding to the weight of the liquid to be dispensed 9 is prepared in advance as control data based on information such as the size of the first container 2 and the weight of the liquid to be dispensed 9. The height position Hp of the liquid level 9s of the liquid to be dispensed is a position represented by the distance from a reference position used by the articulated robot 7, as exemplified in Fig. 11(B) .

[0063] In the dispensing system 1, the articulated robot 7 uses control data for the height position Hp of the liquid surface 9s of the liquid to be dispensed to move the arm 72 and adjust the amount of movement of the pipette tip 4 until the height position Ap of the tip opening 44 of the pipette tip 4 reaches a predetermined stopping position. The predetermined stopping position is a position corresponding to the immersion depth (immersion movement amount) to which the height position Ap of the tip opening 44 of the pipette tip 4 should be immersed from the height position Hp of the liquid surface 9s of the liquid to be dispensed.

[0064] Next, in the dispensing system 1, the pump 6 is operated under the control of the pump control unit 83 of the control device 8 to aspirate the dispensing target liquid 9 into the pipette tip 4 (step S106).

[0065] At this time, the pump 6 is controlled by the pump control section 83 of the control device 8 to operate so as to apply a pressure (suction force) for suction to the dispensing nozzle 5. At this time, the dispensing target liquid 9 is suctioned at a constant suction speed.

[0066] Next, in the dispensing system 1, the central control unit 81 of the control device 8 determines whether the weight loss A1 of the first container 2 has reached a predetermined loss amount D1 (step S107), and continues the operation of aspirating the liquid to be dispensed 9 until the predetermined loss amount D1 is reached.

[0067] When the determination in step S107 is made, the gripping of the first container 2 by the grippers 14a and 14b of the first clamping device 14 has been released. This allows the first weigher 25 to perform accurate weighing without being affected by the gripping by the grippers 14a and 14b.

[0068] The weight loss A1 of the first container 2 is the amount (weight) lost from the initial weight measurement when the first container 2 is placed on the first weighing device 25. The predetermined loss D1 is a weight equivalent to a predetermined aspirated amount of the dispensing target liquid 9. This predetermined loss D1, and therefore the aspirated amount K1, is greater than the weight equivalent to the target dispensing amount Ns to be ultimately dispensed by the dispensing system 1.

[0069] Next, in the dispensing system 1, when the processing unit 811 of the central control unit 81 determines that the weight loss A1 of the first container 2 has reached a predetermined loss amount D1, the control device 8 stops the operation of the pump 6 and terminates the operation of suctioning the dispensing target liquid 9 into the pipette tip 4 (step S108). At this time, the pipette tip 4 absorbs and holds a predetermined amount of the dispensing target liquid 9 therein.

[0070] (Operation of large-volume dispensing of the liquid to be dispensed) Next, in the dispensing system 1, the articulated robot 7 is operated under the control of the robot control unit 82, causing the pipette tip 4 attached to the dispensing nozzle 5 to withdraw from the first container 2 and move to the second container 3 (step S109), and bringing the pipette tip 4 to rest in an upright position above the second container 3 (step S110).

[0071] At this time, the articulated robot 7 moves the arm 72 to raise the hand 75 above the first container 2, causing the pipette tip 4 to withdraw from the first container 2, and then moves the pipette tip 4 to be above the second container 3 placed on the second weigher 35 (see FIG. 12(A)). At this time, the pipette tip 4 is stationary in a substantially vertical position above the opening 32 of the second container 3.

[0072] 12A shows a state in which the tip opening 44 of the pipette tip 4 is stationary at a position slightly above the opening 32 of the second container 3. However, the pipette tip 4 at this time may be configured to move until the tip opening 44 is at approximately the same height as the opening 32 or to a height slightly inside the main body 31 from the opening 32 and then stationary.

[0073] Next, in the dispensing system 1, the pump 6 is operated under the control of the control device 8 to discharge a large amount of the dispensing target liquid 9 from the pipette tip 4 into the second container 3 (step S111).

[0074] At this time, the pump 6 is operated under the control of the pump control unit 83 in the control device 8 to apply pressure (discharge force) for large-volume dispensing to the dispensing nozzle 5. The large-volume dispensing of the liquid to be dispensed 9 at this time is performed at a constant discharge speed. During this large-volume dispensing, the liquid to be dispensed 9 in the pipette tip 4 is dispensed from the distal end opening 44 of the pipette tip 4 as a nearly continuous liquid mass in an amount of one drop or more. Thereafter, during the large-volume dispensing, the liquid mass falls continuously from the opening 32 of the second container 3 into the main body 31 and is stored therein.

[0075] When this large-volume dispensing operation is performed, the central control unit 81 of the control device 8 determines whether or not the entire amount of the dispensing target liquid 9 in the pipette tip 4 has been dispensed (step S112).

[0076] This determination is made by detecting that the weighing result of the second weigher 35 has reached a value equal to the predetermined decrease amount D1 (suction amount K1) in the suction operation. When the determination in step S112 is made, the second clamping device 15 has released the clamping of the second container 3. This allows the second weigher 35 to perform accurate weighing without being affected by the clamping by the grippers 15a and 15b.

[0077] In the dispensing system 1, as shown in Figure 5, if it is determined in step S112 that the entire amount of the liquid to be dispensed 9 has been dispensed, the process returns to step S105 and a second suction and large-volume dispense of the liquid to be dispensed 9 into the pipette tip 4 is performed.

[0078] In this case, after the first large-volume dispensing of the target liquid 9 is completed, the pipette tip 4 is moved to the first container 2, and the aspirating operation of the target liquid 9 (steps S105 to S108) is performed again. The aspirated volume K2 (amount of decrease D2 from the first container 2) aspirated in the second aspirating operation is, for example, less than the first aspirated volume K1 (amount of decrease D1) and slightly greater than the target dispensing volume Ns minus the first decrease D1. Next, the pipette tip 4 after the second aspirating operation is moved to the second container 3, and the second large-volume dispensing operation of the target liquid 9 is performed (steps S109 to S112). Incidentally, as shown in FIG. 5 , a third and subsequent aspirating and large-volume dispensing operations are repeated until it is determined in step S112 after the second large-volume dispensing operation that the entire amount of the target liquid 9 has not been dispensed.

[0079] Furthermore, in the dispensing system 1, as shown in FIG. 5, if it is determined in step S112 that the entire amount of the liquid to be dispensed 9 has not been ejected, the central control unit 81 of the control device 8 determines whether the weight increase A2 of the second container 3 has reached a predetermined increase N1 (step S113).

[0080] At this time, the weight increase A2 of the second container 3 is obtained from the weighing result of the second weighing device 35. The predetermined increase N1 is a weight equivalent to the target dispensing amount Ns minus the amount required for dispensing a small or minute amount of the next dispensing target liquid 9.

[0081] 5, in the dispensing system 1, if it is determined in step S113 that the weight increase A2 of the second container 3 has not reached the predetermined increase N1, the large-volume dispensing continues and the determinations of steps S112 and S113 are repeated. On the other hand, in the dispensing system 1, if it is determined in step S113 that the weight increase A2 of the second container 3 has reached the predetermined increase N1, the operation of the pump 6 is stopped by the control of the control device 8, and the large-volume dispensing operation is terminated (step S114).

[0082] (Operation of dispensing a small amount of the liquid to be dispensed) Next, in the dispensing system 1, when the large amount of the liquid to be dispensed 9 is dispensed in step S114, as shown in Figure 6, the pump 6 is operated under the control of the control device 8 to dispense a small amount of the liquid to be dispensed 9 from the pipette tip 4 into the second container 3 (step S115).

[0083] At this time, the pump 6 is operated under control of the pump control unit 83 of the control device 8 to apply pressure (pushing force) to the dispensing nozzle 5 for dispensing a small amount. This small amount of dispensing is performed by dispensing the liquid 9 to be dispensed from the tip opening 44 of the pipette tip 4 in the form of approximately one drop at a predetermined interval, and allowing the liquid to fall sequentially into the main body 31 of the second container 3 and be stored therein. For example, when the liquid 9 to be dispensed is water, the pump 6 during this small amount of dispensing is controlled under conditions such that the syringe of the syringe pump serving as the pump 6 is moved a predetermined distance (amount) to dispense a 0.05 ml droplet of water (corresponding to one droplet that can fall from the tip opening 44 of the pipette tip 4 due to gravity) from the tip opening 44 of the pipette tip 4. Furthermore, the pump 6 is controlled under conditions such that the small amount of water droplets are dispensed at intervals of approximately 1 to 2 seconds. The reason why small amounts are dispensed at intervals is that it is necessary to determine whether the weight increase A2 of the second container 3, which will be described later, has reached a predetermined increase N2 each time one droplet 9a is dispensed. The syringe pump used here is capable of controlling the amount of dispensed liquid with a resolution of, for example, 0.01 ml.

[0084] 12(B), in the same manner as in the large-volume dispensing operation, the liquid to be dispensed 9 in the pipette tip 4 is dispensed at predetermined intervals as at least one droplet 9a from the distal end opening 44 of the pipette tip 4. Each droplet dispensed in this small-volume dispensing operation intermittently falls from the opening 32 of the second container 3 into the main body 31 and is successively collected.

[0085] When the small-volume dispensing operation is performed, the central control unit 81 of the control device 8 determines whether the weight increase A2 of the second container 3 has reached a predetermined increase N2 (step S116). The weight increase A2 of the second container 3 is the amount of weight increase of the second container 3 after the large-volume dispensing operation has been completed. The predetermined increase N2 is a weight equivalent to the target dispensing volume Ns minus the amount required to dispense the next small amount of the dispensing target liquid 9.

[0086] 6, in the dispensing system 1, if it is determined in step S116 that the weight increase A2 of the second container 3 has not reached the predetermined increase N2, the small-amount dispensing continues and the determination in step S116 is repeated. On the other hand, in the dispensing system 1, if it is determined in step S116 that the weight increase A2 of the second container 3 has reached the predetermined increase N2, the central control unit 81 of the control device 8 determines whether the weight increase A2 of the second container 3 has reached the target dispensing amount Ns (step S117).

[0087] If it is determined in step S117 that the weight increase A2 of the second container 3 has not reached the target dispensing amount Ns, the control device 8 stops the operation of the pump 6 to terminate the small-volume dispensing operation (step S118). On the other hand, if it is determined in step S117 that the weight increase A2 of the second container 3 has reached the target dispensing amount Ns, one dispensing operation is terminated (step S122). When the small-volume dispensing is performed, the second container 3 contains the liquid 9 to be dispensed by the small-volume dispensing in addition to the liquid 9 to be dispensed that was contained in the large-volume dispensing.

[0088] When the small amount of dispensing is completed in step S118, the central control unit 81 of the control device 8 determines whether or not re-suction of the dispensing target liquid 9 is necessary (step S119).

[0089] This determination is made as follows. First, the amount obtained by subtracting the weight of the liquid to be dispensed 9 contained in the second container 3 after small-scale dispensing from the target dispensing volume Ns can be considered to be the weight equivalent to the remaining amount of liquid to be dispensed 9 in the pipette tip 4. Then, in the dispensing system 1, it is necessary to perform the next micro-dispensing using the remaining amount of liquid to be dispensed 9 in the pipette tip 4 after small-scale dispensing to reach the target dispensing volume Ns and complete the dispensing operation equivalent to at least one cycle. For this reason, in the dispensing system 1, if it is expected that the target dispensing volume Ns will not be reached even if the next micro-dispensing is performed using the remaining amount of liquid to be dispensed 9 in the pipette tip 4 after small-scale dispensing, the dispensing system 1 is configured to perform re-aspiration to replenish the liquid to be dispensed 9.

[0090] Therefore, the determination in step S119 is made by determining whether or not the remaining amount of the dispensing target liquid 9 in the pipette tip 4 exceeds a predetermined minimum amount. The predetermined minimum amount in this case is set to an appropriate amount, for example, by conducting a test or the like in advance.

[0091] In the dispensing system 1, as shown in FIG. 6, if it is determined in step S119 that re-suction of the liquid to be dispensed 9 is not necessary, the control device 8 operates the articulated robot 7 and the pump 6 to perform minute amount discharge (step S120).

[0092] On the other hand, in the dispensing system 1, as shown in FIG. 6, if it is determined in step S119 that re-aspiration of the dispensing target liquid 9 is necessary, the re-aspiration operation described below is performed.

[0093] 7, in the dispensing system 1, the articulated robot 7 is operated under the control of the robot control unit 82 to move the pipette tip 4 attached to the dispensing nozzle 5 from the second container 3 to the first container 2, and then the tip of the pipette tip 4 is inserted into the first container 2 (step S150). Next, in the dispensing system 1, the pump 6 is operated under the control of the pump control unit 83 to aspirate the liquid 9 to be dispensed into the pipette tip 4 (step S151).

[0094] The aspirating operation of the dispensing target liquid 9 during this re-aspiration is basically the same as the operation in step S105, except for the operation described below. During this re-aspiration, the central control unit 81 of the control device 8 determines whether the weight loss A1 of the first container 2 has reached a predetermined loss amount D2 (step S152), and continues the aspirating operation of the dispensing target liquid 9 until the predetermined loss amount D2 is reached. The predetermined loss amount D2 corresponds to the aspirating amount K2 and is an amount that is expected to reach the target dispensing amount Ns with the next minute dispensing. More specifically, the loss amount D2 is an amount that allows minute dispensing and that prevents the dispensing target liquid 9 in the pipette tip 4 from contacting a portion of the dispensing nozzle 5 when the pipette tip 4 is in the tilted position.

[0095] In the dispensing system 1, when it is determined that the weight loss A1 of the first container 2 has reached the predetermined weight loss D2 during this re-aspiration, the pump control unit 83 controls the pump 6 to stop operation (step S153). Next, in the dispensing system 1, the robot control unit 82 controls the articulated robot 7 to remove the pipette tip 4 from the first container 2 and move it to the second container 3 (step S154), and then the pipette tip 4 is stopped in an upright position on the second container 3 (step S155).

[0096] Then, in the dispensing system 1, if it is determined in step S119 that re-suction is not necessary, the process proceeds to the next minute amount of dispensing (step S120).

[0097] 8, the minute amount of the liquid to be dispensed 9 is dispensed by closing the grippers 15a and 15b of the second clamping device 15 under the control of the positioning clamping control section 84 of the control device 8 to clamp and hold the second container 3 (step S201). As a result, the second container 3 is placed in a stable state at a predetermined position on the weighing dish 36 of the second weighing device 35 (see FIG. 10).

[0098] Next, in the dispensing system 1, as shown in Figures 7 and 13, the articulated robot 7 is operated under the control of the robot control unit 82, and the pipette tip 4, which is stationary in an upright position (see Figure 13(A)), is changed to an inclined position (see Figure 13(B)) (step S202).

[0099] At this time, the articulated robot 7 rotates a portion of the arm 72 to a predetermined angle to tilt the dispensing nozzle 5. As a result, the pipette tip 4 attached to the dispensing nozzle 5 assumes a posture in which the center line, indicated by the dashed line in the internal passage 55 (see FIG. 3), is tilted at a predetermined tilt angle α with respect to the imaginary line VL that runs along the inner wall surface 31a of the main body 31 of the second container 3, as shown in FIG. 13(B). The tilt angle α can be set as appropriate, but is set to an angle within the range of 15 to 75°, for example, and preferably within the range of 45 to 75°.

[0100] Here, if the opening 32 of the second container 3 is a container having a smaller diameter than the main body 31, the tilt angle α of the pipette tip 4 may be an imaginary straight line along the inner wall surface of the smaller diameter opening 32. Also, Fig. 13(B) illustrates an example in which the operation of changing the pipette tip 4 to a tilted position is performed when the pipette tip 4 is positioned above and away from the opening 32 of the second container 3. However, the operation of changing to the tilted position may also be configured to be performed, for example, when the distal opening 44 of the pipette tip 4 is at the same height as the opening 32 of the second container 3 or at a position further inward than the opening 32.

[0101] Next, in the dispensing system 1, the pump 6 is operated under the control of the pump control unit 83, causing a portion 9b of the liquid 9 to be dispensed in the pipette tip 4 to protrude from the tip opening 44 of the pipette tip 4 as shown in Figure 15 (A), and then the operation of the pump is stopped so that the portion 9b of the liquid 9 to be dispensed remains in the protruding position from the tip opening 44 (step S203).

[0102] At this time, the pump 6 operates under the control of the pump control unit 83 of the control device 8 to exert a pressure (pushing force) required for minute-amount dispensing on the dispensing nozzle 5 and to stop (maintain) that pressure state. The amount of operation of the pump 6 required for this minute-amount dispensing is an amount that allows a portion 9b of the liquid to be dispensed 9 to protrude and stop from the tip opening 44 of the pipette tip 4. The state in which a portion 9b of the liquid to be dispensed 9 protrudes and stops from the tip opening 44 of the pipette tip 4 means that the portion 9b protrudes from the tip opening 44 and does not fall off the tip opening 44 under its own weight.

[0103] Furthermore, the portion 9b of the liquid 9 to be dispensed that protrudes and stops at the tip opening 44 is adjusted to be an amount smaller than a single drop 9d of the liquid 9 to be dispensed (see FIG. 15C ). In the case where the liquid 9 to be dispensed is water, for example, the pump 6 during this minute amount dispensing is controlled under conditions such that the syringe of the syringe pump serving as the pump 6 is moved a predetermined distance (amount) so that approximately 0.03 ml of water protrudes and stops at the tip opening 44 of the pipette tip 4. The control conditions of the pump 6 at this time are set appropriately taking into consideration information such as the type of liquid 9 to be dispensed and the surface tension of the tip opening 44 of the pipette tip 4 relative to the liquid 9 to be dispensed.

[0104] 13(B), the dispensing system 1 performs the operation of changing the pipette tip 4 to a tilted position when the pipette tip 4 is positioned above and away from the opening 32 of the second container 3. Therefore, in the dispensing system 1, before performing the operation of step S203, the arm 72 of the articulated robot 7 is actuated to move the tilted pipette tip 4 to a position where the distal opening 44 approaches the inner wall surface 31a of the second container 3 at a predetermined distance (see FIG. 15(A)).

[0105] Furthermore, in the dispensing system 1, as shown in FIG. 8, almost simultaneously with the operation of step S203, the articulated robot 7 is operated under the control of the robot control unit 82 to complete one micro-dispensing operation as described below.

[0106] That is, in one micro-dispensing operation, by moving the arm portion 72 of the articulated robot 7, the tip opening 44 of the pipette tip 4 after the operation of step S203 is brought into contact with the inner wall surface 31a of the second container 3 once (see Figure 15 (B)), and then the dispensing nozzle 5 is moved so that the tip opening 44 of the pipette tip 4 is separated from the inner wall surface 31a of the second container 3 (see Figure 15 (C)) (step S204).

[0107] 15(B), the first half of step S204 causes a portion 9b of the liquid to be dispensed 9 that protrudes from the distal opening 44 of the pipette tip 4 and stops thereto to come into contact with the inner wall surface 31a of the second container 3. As a result, almost the entire portion 9b of the liquid to be dispensed 9 that protrudes from the distal opening 44 of the pipette tip 4 is attached to the inner wall surface 31a of the second container 3.

[0108] Next, by the operation of the latter half of step S204, a portion 9b of the liquid to be dispensed 9 adhering to the inner wall surface 31a of the second container 3 is separated from the distal opening 44 of the pipette tip 4, as shown in Figure 15(C). As a result, the portion 9b of the liquid to be dispensed 9 moves downward along the inner wall surface 31a of the second container 3 due to its own weight, and is eventually contained in the second container 3. The portion 9b of the liquid to be dispensed 9 dispensed during this minute amount dispensing is smaller in amount than the independent drop 9d of the liquid to be dispensed 9 shown by imaginary lines in Figure 15(C). Furthermore, the drop 9d at this time also corresponds to a drop of liquid dispensed each time a small amount is intermittently dispensed.

[0109] Therefore, according to this dispensing system 1, by performing a micro-dispensing operation using the articulated robot 7, the liquid to be dispensed 9 can be dispensed from the pipette tip 4 into the second container 3 in an amount less than one drop.

[0110] 8, in the dispensing system 1, under the control of the positioning and clamping control unit 84, the grippers 15a and 15b of the second clamping device 15 in the positioning device 13 open to release the clamping of the second container 3 (step S205). This allows the second weigher 35 to perform accurate weighing without being affected by the clamping by the grippers 15a and 15b of the second clamping device 15.

[0111] 8, the central control unit 81 of the dispensing system 1 determines whether the weight increase A3 of the second container 3 has reached the target dispensing amount Ns (step S206). The weight increase A3 of the second container 3 is the amount of further increase in the weight of the second container 3 after the small-volume dispensing is completed.

[0112] In the dispensing system 1, as shown in Figure 8, if it is determined in step S206 that the weight increase A3 of the second container 3 does not reach the target dispensing amount Ns, the positioning clamping control unit 84 of the control device 8 controls the second clamping device 15 to close the grippers 15a and 15b and hold the second container 3 in a clamped state again (step S207).

[0113] In this case, the dispensing system 1 repeats the operations of steps S203 to S206 in the same manner to perform a second minute-amount dispensing, as shown in Figure 8. In this second minute-amount dispensing as well, the amount of the dispensing target liquid 9 dispensed at that time is less than one drop 9d of the dispensing target liquid 9. This also applies to the third and subsequent minute-amount dispensings.

[0114] 6 and 8, in the dispensing system 1, when it is determined in step S206 that the weight increase A3 of the second container 3 has reached the target dispensing amount Ns, the central control unit 81 of the control device 8 terminates the micro-dispensing operation (step S121). As a result, the dispensing target liquid 9 in an amount that has reached the target dispensing amount Ns is dispensed and stored in the second container 3.

[0115] In the dispensing system 1, as shown in Figure 6, when the small amount dispensing operation is completed or when the weight increase A3 of the second container 3 reaches the target dispensing amount Ns due to small amount dispensing, one dispensing operation is considered to be completed (step S121).

[0116] For reference, in the operation of the micro-dispensing operation, if the tilt angle β when the pipette tip 4 is tilted as illustrated in Figure 16 (A) is smaller than the tilt angle α, the tip opening 44 of the pipette tip 4 may touch the inner wall surface 31a of the second container 3 before the liquid to be dispensed 9 inside the pipette tip 4. Furthermore, even when the pipette tip 4 is tilted at the tilt angle α, if the operation of step S203 (the operation of causing a portion 9b of the liquid to be dispensed 9 to protrude from the tip opening 44 of the pipette tip 4) is not performed, the tip opening 44 of the pipette tip 4 is likely to touch the inner wall surface 31a of the second container 3 before the liquid to be dispensed 9 inside the pipette tip 4. If the tip opening 44 of the pipette tip 4 touches the inner wall surface 31a of the second container 3 before the liquid to be dispensed 9 inside the pipette tip 4 in this way, it is difficult or impossible to perform micro-dispensing.

[0117] (Operation after one dispensing operation is completed) Next, in the dispensing system 1, as shown in Figure 6, the articulated robot 7 is operated under the control of the robot control unit 82, and the pipette tip 4 is withdrawn from the second container 3 while remaining in an inclined position (step S123).

[0118] At this time, when one dispensing operation is completed by completing the minute-amount dispensing, the articulated robot 7 activates the arm 72 to raise the pipette tip 4, which is in a tilted position after the minute-amount dispensing operation has been completed, and the dispensing nozzle 5 (see FIG. 14(A)), in that tilted position, almost vertically above the second container 3. As a result, the pipette tip 4, which is in a tilted position after the minute-amount dispensing operation has been completed, is retracted from the second container 3 (see FIG. 13(B)).

[0119] In contrast, for example, if the pipette tip 4, which has completed one dispensing operation after a small amount of dispensing, is withdrawn from the second container 3 in a substantially vertically upright position, there is a risk of the remaining dispensing target liquid 9 dripping from the distal end opening 44 of the pipette tip 4. In this regard, in the dispensing system 1, the pipette tip 4, which is in a tilted position after the small amount of dispensing operation is withdrawn from the second container 3 in that tilted position, and therefore such dripping can be avoided.

[0120] Furthermore, in the dispensing system 1, it is possible that a single dispensing operation will end during the small-volume dispensing operation process based on the determination result of step S117. In this case, the articulated robot 7 operates the arm 72 to raise the upright pipette tip 4 and, in turn, the dispensing nozzle 5 (see FIG. 12A) almost vertically above the second container 3 while maintaining the upright position. In this case, when the process proceeds to step S126 (described later), the pipette tip 4 is moved to the tip disposal unit 16 while still in the upright position.

[0121] The reason why the pipette tip 4 is withdrawn from the second container 3 in an upright position when one dispensing operation is completed at this small-volume dispensing stage, or further, moved to the tip disposal unit 16 in an upright position, is as follows: If the pipette tip 4 after one dispensing operation at the small-volume dispensing stage is tilted and then returned to an upright position and moved to the tip disposal unit 16, etc., the amount of the dispensing target liquid 9 remaining in the pipette tip 4 is larger than the minute amount of the dispensing target liquid 9 remaining at the end of the minute-volume dispensing, for example, and therefore dripping from the tip opening 44 is likely to occur. In this regard, if the pipette tip 4 after one dispensing operation at the small-volume dispensing stage is withdrawn from the second container 3 in an upright position or moved to the tip disposal unit 16 in an upright position, the occurrence of dripping can be avoided.

[0122] Next, in the dispensing system 1, as shown in FIG. 6, the central control unit 81 determines whether or not there is a next dispensing operation of the same type of dispensing target liquid 9 (step S124).

[0123] In the dispensing system 1, if it is determined in step S124 that there is no next dispensing operation of the same type of dispensing target liquid 9, as shown in Figure 6, the central control unit 81 determines whether there is a next dispensing operation of a different type of dispensing target liquid 9 (step S124).

[0124] If it is determined in step S124 that there is no next dispensing operation of a different type of dispensing target liquid 9, the articulated robot 7 is operated under the control of the robot control unit 82, and the pipette tip 4 after one dispensing operation is moved to the tip disposal unit 16, as shown in Figure 6 (step S126).

[0125] Next, the dispensing system 1 removes the pipette tip 4 that has been moved to the tip disposal unit 16 from the dispensing nozzle 5 (step S127). At this time, the arm unit 72 of the articulated robot 7 inserts the pipette tip 4 attached to the dispensing nozzle 5 into the tip disposal unit 16 through a disposal port so that a portion of the pipette tip 4 is hooked on a tip hook (not shown), and then moves the dispensing nozzle 5 upward. As a result, the pipette tip 4 is disengaged from the dispensing nozzle 5 and removed from the dispensing nozzle 5. The removed pipette tip 4 falls into a waste storage box in the tip disposal unit 16 and is collected.

[0126] Next, in the dispensing system 1, as shown in FIG. 6, the articulated robot 7 is operated under the control of the robot control unit 82 to remove the dispensing nozzle 5 from the hand unit 75 and return it to the holding stand 56 (step S128).

[0127] At this time, the articulated robot 7 moves the arm unit 72 to move the hand unit 75 to a position close to the holding stand 56 and inserts the lower part of the gripped portion 53 of the dispensing nozzle 5 into the recess of the holding portion 57 of the holding stand 56, and then opens the grippers 76b, 76c of the gripper device 76 in the hand unit 75 to release the gripped portion 53 of the dispensing nozzle 5. As a result, the dispensing nozzle 5 is once again held by the holding stand 56. At the same time, the dispensing nozzle 5 is removed from the hand unit 75 of the articulated robot 7.

[0128] (Operation when there is a next dispensing operation of the same type of dispensing target liquid 9) In the dispensing system 1, if it is determined in step S124 that there is a next dispensing operation of the same type of dispensing target liquid 9, the second container 3 after dispensing is removed from the weighing dish 36 of the second weigher 35 and placed in a predetermined location, and then the next second container 3 is placed on the weighing dish 36 of the second weigher 35 as shown in Fig. 6 (step S131). In this dispensing system 1, the removal of the second container 3 after dispensing and the placement of the next second container 3 are performed manually by an operator or the like. However, if the dispensing system 1 is configured to automatically perform operations such as grasping the second container 3, the removal of the second container 3 and the placement of the next second container 3 will also be performed automatically.

[0129] In this case, since the dispensing target liquid 9 is the same type, the dispensing system 1 can be used repeatedly without replacing the pipette tip 4. After the next second container 3 is placed on the weighing dish 36 of the second weighing device 35, the dispensing system 1 proceeds to step S105 (see FIG. 5) and repeats the second dispensing operation.

[0130] The dispensing system 1 may be configured to replace the pipette tip 4 and perform the next dispensing operation when it is determined that there is a next dispensing operation of the same type of dispensing target liquid 9. In this case, the process may proceed from step S131 to step S103, and then the second dispensing operation may be repeated.

[0131] (Operation when a different type of dispensing target liquid 9 is next to be dispensed) Furthermore, in the dispensing system 1, if it is determined in step S125 that a different type of dispensing target liquid 9 is next to be dispensed, as shown in Fig. 6, the first container 2 after one dispensing operation is completed is removed from the weighing dish 26 of the first weigher 25 and placed in a predetermined location, and then the first container 2 containing the next, different type of dispensing target liquid 9 is placed on the weighing dish 26 of the first weigher 25 (step S132), as shown in Fig. 6. In this dispensing system 1, the removal of the first container 2 after one dispensing operation is completed and the placement of the next first container 2 are performed manually by an operator or the like. However, if the dispensing system 1 is configured so that operations such as grasping the first container 2 are performed automatically by an articulated robot or the like, the removal of the first container 2 and the placement of the next first container 2 will also be performed automatically.

[0132] In this case, since the dispensing target liquid 9 is a different type, the dispensing system 1 replaces the pipette tip 4 and uses a new pipette tip 4. Therefore, as shown in Figures 5 and 6, the dispensing system 1 proceeds to step S104, attaches a new pipette tip 4 to the dispensing nozzle 5, and then repeats the dispensing operation for the different type of dispensing target liquid 9. Incidentally, the amounts used when determining the target dispensing amount Ns, etc. in the next dispensing operation for the different type of dispensing target liquid 9 are normally set to different amounts, but all or part of the amounts may be set to the same amount.

[0133] (Effect of dispensing by dispensing system) As described above, according to the dispensing system 1, by performing a micro-dispensing operation using the articulated robot 7, the liquid to be dispensed 9 can be dispensed from the pipette tip 4 into the second container 3 in an amount less than one drop.

[0134] Furthermore, according to the dispensing system 1, the dispensing of the liquid to be dispensed 9 is performed not only by a small amount dispensing operation, but also by a combination of a large amount dispensing operation and a small amount dispensing operation, so that even if the target dispensing amount Ns is relatively large, the dispensing operation can be performed efficiently and quickly.

[0135] Furthermore, since the dispensing operation is almost entirely automated with the dispensing system 1, it can be performed more quickly and accurately than manual dispensing. Moreover, if the dispensing target liquid 9 is harmful to the human body if it comes into contact with the human body, the dispensing system 1 makes it possible to dispense the dispensing target liquid 9 safely without adversely affecting the human body.

[0136] In addition, in the dispensing system 1, the pipette tip 4 is tilted at an angle of inclination α when dispensing a small amount of liquid, but even when tilted at the angle of inclination α, the amount of the liquid to be dispensed 9 contained in the pipette tip 4 at that time is adjusted. Therefore, as illustrated in FIG. 16(B), there is no risk that the liquid surface 9s of the liquid to be dispensed 9 contained in the tilted pipette tip 4 will come into contact with and adhere to the attachment portion 52 of the dispensing nozzle 5 fitted into the attachment portion 43 of the pipette tip 4. As a result, with the dispensing system 1, even when different types of liquid to be dispensed 9 are successively dispensed, the previous type of liquid to be dispensed 9 that has adhered to the attachment portion 52 of the dispensing nozzle 5 will not mix with the subsequent type of liquid to be dispensed 9 in the tilted pipette tip 4, thereby preventing contamination.

[0137] 16B, if the tilt angle of the pipette tip 4 during micro-dispensing is set to a tilt angle δ greater than the tilt angle α, the liquid surface 9s of the liquid to be dispensed contained in the pipette tip 4 may come into contact with and adhere to the attached portion 52 of the dispensing nozzle 5 fitted into the attachment portion 43 of the pipette tip 4, thereby inducing contamination. For this reason, it is preferable to set the tilt angle α of the pipette tip 4 during micro-dispensing to an angle smaller than the tilt angle δ at which the liquid to be dispensed 9 may adhere to the attached portion 52 of the dispensing nozzle 5.

[0138] (Modifications) The present invention is not limited to the configurations exemplified as the above-described embodiments, and modifications and alterations such as additions, substitutions, and combinations of configurations are possible as needed.

[0139] The dispensing system 1 may be configured, for example, so that the operation of placing the first container 2 on the first weigher 25 and the operation of placing the second container 3 on the second weigher 35 are performed by the articulated robot 7. In this configuration, automation of the dispensing operation is enhanced. In addition, in this configuration, the operations of steps S101 and S102 shown in FIG. 5 are automatically performed by the articulated robot 7 in the dispensing system 1.

[0140] A container with a lid may be used as one or both of the first container 2 and the second container 3. In this case, as described above, the operations of opening and closing the lid of the first container 2 and the lid of the second container 3 may be configured to be performed automatically by using another articulated robot, a lid opening and closing device, etc. This configuration also enhances the automation of the dispensing operation.

[0141] (Summary) The present invention includes a second invention, which is a dispensing system according to the first invention, in which the tilted position is a position in which the liquid to be dispensed exposed at the distal opening of the pipette tip touches the inner wall of the second container before the distal opening. According to this second invention, the liquid to be dispensed can be dispensed more accurately from the pipette tip in amounts less than one drop, compared to when the tilted position is a position in which the distal opening of the pipette tip touches the inner wall of the second container before the liquid to be dispensed exposed at the distal opening.

[0142] The present invention also includes a third invention in which, in the dispensing system of the first or second invention, the control device operates the pump so that the liquid to be dispensed in the pipette tip protrudes from the tip opening and stops before the tip opening of the pipette tip touches the inner wall of the second container. According to this third invention, the liquid to be dispensed exposed from the tip opening of the pipette tip comes into contact with the inner wall of the second container before the tip opening, thereby ensuring the discharge of a small amount.

[0143] The present invention includes a fourth invention in which, in the dispensing system of any one of the first to third inventions, in the micro-dispensing operation, the amount of the dispensing target liquid in the pipette tip is adjusted to a liquid amount that does not come into contact with the dispensing nozzle when the pipette tip is in the tilted position. According to this fourth invention, when different types of dispensing target liquids are successively dispensed, it is possible to prevent contamination, in which the dispensing target liquid adhering to the dispensing nozzle mixes with the different types of dispensing target liquid.

[0144] The present invention includes a fifth invention in which, in the dispensing system of any one of the first to fourth inventions, the control device performs a withdrawal operation of moving the dispensing nozzle by the articulated robot so that the pipette tip withdraws from the second container while maintaining the tilted attitude after the micro-dispensing operation is completed. According to this fifth invention, it is possible to prevent the liquid to be dispensed remaining in the pipette tip after the micro-dispensing operation has been completed from falling into the second container during the withdrawal operation.

[0145] The present invention includes a sixth invention in which the dispensing system of any one of the first to fifth inventions further includes a first scale on which the first container is placed and which weighs the liquid to be dispensed contained in the first container, and a second scale on which the second container is placed and which weighs the liquid to be dispensed dispensed into the second container, and the control device controls the operation of the pump and the articulated robot using information on the weighing results of the first scale and the second scale. According to the sixth invention, the pump and the articulated robot can be operated appropriately in accordance with the amount of liquid to be dispensed in the first container and the amount of liquid to be dispensed in the second container, respectively.

[0146] The present invention includes a seventh invention in which, in the dispensing system of the sixth invention, the control device moves the dispensing nozzle by the articulated robot so as to adjust the position of the tip opening of the pipette tip within the first container using information on the weighing result of the first weigher during an aspirating operation of aspirating the dispensing target liquid from the first container into the pipette tip. According to the seventh invention, during the aspirating operation, the position of the tip opening of the pipette tip within the first container can be adjusted without using information obtained by analyzing image information from a camera.

[0147] The present invention includes an eighth invention in which the dispensing system of the sixth invention further includes a first clamping device that clamps and positions the first container placed on the first weighing device, and a second clamping device that clamps and positions the second container placed on the second weighing device, and the operations of the first clamping device and the second clamping device are controlled by the control device. According to the eighth invention, the position of the first container on the first weighing device and the position of the second container on the second weighing device are determined to be the same, and pipette tips can be accurately moved relative to the first container and the second container to perform operations.

[0148] The present invention includes a ninth invention in which, in the dispensing system of the eighth invention, the control device controls to release clamping of the first clamping device when performing weighing with the first weigher, and to release clamping of the second clamping device when performing weighing with the second weigher. According to the ninth invention, weighing with the first weigher is performed accurately without being affected by clamping by the first clamping device, and weighing with the second weigher is performed accurately without being affected by clamping by the second clamping device.

[0149] The present invention includes a tenth invention in which, in the dispensing system of any one of the first to ninth inventions, the pipette tip is detachably attached to the dispensing nozzle, and the control device performs a removal operation of moving the dispensing nozzle using the articulated robot so that the pipette tip can be removed from the dispensing nozzle after dispensing is completed. According to the tenth invention, different types of dispensing target liquids can be dispensed while avoiding contamination.

[0150] DESCRIPTION OF SYMBOLS 1... Dispensing system 2... First container 3... Second container 4... Pipette tip 5... Dispensing nozzle 7... Articulated robot 8... Control device 9... Liquid to be dispensed 9b... Part of the liquid to be dispensed that protrudes and is exposed at the tip opening of the pipette tip 14... First clamping device 15... Second clamping device 25... First weighing device 31a... Inner wall surface (an example of the inner wall of the second container) 35... Second weighing device 44... Tip opening Hp... Height position of the tip opening of the pipette tip within the first container

Claims

a pump that exerts pressure on the dispensing nozzle to draw in and dispense liquid; an articulated robot that holds the dispensing nozzle and moves to perform a plurality of tasks; and a control device that controls the operation of the pump and the articulated robot, wherein the control device performs an operation of moving the dispensing nozzle using the articulated robot so that the pipette tip that has drawn in the liquid to be dispensed is tilted from an upright position to a tilted position, and then the tip of the pipette tip touches and releases the inner wall of the second container once, as a micro-dispensing operation of dispensing a micro-amount of the liquid to be dispensed from the pipette tip into the second container.

2. A dispensing system as described in claim 1, wherein the tilted position is a position in which the liquid to be dispensed exposed at the tip opening of the pipette tip touches the inner wall of the second container before the tip opening.

3. The dispensing system according to claim 2, wherein the control device operates the pump so that the liquid to be dispensed in the pipette tip protrudes from the tip opening and stops before the tip opening of the pipette tip touches the inner wall of the second container.

4. A dispensing system as described in claim 2, wherein, during the micro-dispensing operation, when the pipette tip is in the tilted position, the amount of liquid to be dispensed in the pipette tip is adjusted so that it does not come into contact with the dispensing nozzle.

5. The dispensing system of claim 1, wherein the control device performs an exit operation in which the articulated robot moves the dispensing nozzle so that the pipette tip remains in the tilted position when the micro-dispensing operation is completed and then exits the second container.

6. A dispensing system as described in claim 1, comprising: a first weighing scale on which the first container is placed and which weighs the weight of the liquid to be dispensed contained in the first container; and a second weighing scale on which the second container is placed and which weighs the weight of the liquid to be dispensed dispensed into the second container, wherein the control device controls the operation of the pump and the articulated robot while using information on the weighing results of the first weighing scale and the second weighing scale.

7. The dispensing system of claim 6, wherein the control device, during an aspiration operation of aspirating the liquid to be dispensed from the first container into the pipette tip, moves the dispensing nozzle using the articulated robot so as to adjust the position of the tip opening of the pipette tip within the first container using information on the weighing result of the first weighing device.

8. A dispensing system as described in claim 6, comprising a first clamping device that clamps and positions the first container placed on the first weighing device, and a second clamping device that clamps and positions the second container placed on the second weighing device, wherein the operation of the first clamping device and the second clamping device are controlled by the control device.

9. A dispensing system as described in claim 8, wherein the control device controls the first clamping device to release the clamping when weighing is performed using the first weighing device, and controls the second clamping device to release the clamping when weighing is performed using the second weighing device.

10. A dispensing system as described in claim 1, wherein the pipette tip is removably attached to the dispensing nozzle, and the control device performs a removal operation in which the articulated robot moves the dispensing nozzle so that the pipette tip is removed from the dispensing nozzle after dispensing is completed.

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