Automatic analyzer and automatic analysis method

1. An automatic analyzer equipped with functions to perform optical measurement and reaction vessel cleaning, comprising:

a control unit configured for controlling a sequence including the optical measurement and the reaction vessel cleaning;

a discharge mechanism including a discharge nozzle configured for discharging a liquid into the reaction vessel and operative to vertically move up and down the discharge nozzle and to discharge the liquid; and

an overflow suction mechanism including an overflow suction nozzle configured for sucking an overflow amount of the liquid in the reaction vessel and operative to vertically move up and down the overflow suction nozzle and to suck the overflow amount of liquid, wherein

in a liquid discharge step which is included in the reaction vessel cleaning preceding the optical measurement and which is interposed between a preceding step using a detergent and a succeeding blank value measurement step, the control unit provides control so as to carry out the discharge of the liquid from the discharge nozzle and the suction of the overflow amount of liquid through the overflow suction nozzle when the automatic analyzer is in a first state where a lower end of the discharge nozzle is located at a first position in a heightwise lower part of the reaction vessel by a downward movement of the discharge mechanism and a lower end of the overflow suction nozzle is located at a second position in a heightwise upper part of the reaction vessel by a downward movement of the overflow suction mechanism,

an opening mouth at the lower end of the discharge nozzle has a slant face at a cutting angle of 10 degrees or more, and

the slant face is directed to the overflow suction nozzle as seen from the discharge nozzle.

2. The automatic analyzer according to claim 1 , wherein

the first position is in a first range from an inside bottom of the reaction vessel to one third of the height of an inside wall of the reaction vessel.

3. The automatic analyzer according to claim 2 , wherein

when controlling the downward movement, the control unit starts the discharge of the liquid at the point of time when the lower end of the discharge nozzle is in the first range and at a position just before the first position.

4. The automatic analyzer according to claim 1 , wherein

the second position is a position in vicinity to a top side of the reaction vessel and in a range from the top side of the reaction vessel to 95% of the height of the inside wall of the reaction vessel, or the highest position in all the steps of the reaction vessel cleaning.

5. The automatic analyzer according to claim 1 , wherein

in the first state, the control unit controls the discharge nozzle so as to discharge a predetermined amount of liquid in a range from 97% to 110% of the cubic capacity of the reaction vessel in order that a surface of the liquid reaches the second position.

6. The automatic analyzer according to claim 1 , wherein

after stopping the liquid discharge and liquid suction in the first state, the control unit controls the discharge mechanism so as to move upward to extract the lower end of the discharge nozzle from inside of the reaction vessel and controls the suction mechanism so as to move upward to extract the lower end of the overflow suction nozzle from inside of the reaction vessel.

7. The automatic analyzer according to claim 1 , wherein

when controlling the upward movement, the control unit sets the movement to a first rise speed in a first period until the lower end of the discharge nozzle leaves the surface of the liquid and sets the movement to a higher second rise speed relative to the first rise speed in a second period after the lower end of the discharge nozzle leaves the surface of the liquid.

8. The automatic analyzer according to claim 1 , wherein

the control unit starts the suction by the overflow suction nozzle after the point of time when the discharge of liquid from the discharge nozzle is started and before the point of time when the surface of the liquid reaches the second position.

9. The automatic analyzer according to claim 1 , wherein

the discharge nozzle and the overflow suction nozzle are coupled together and are integrally controlled to move.

10. The automatic analyzer according to claim 1 , further comprising a disk mechanism on which a plurality of reaction vessels as the reaction vessel are arranged on a circle and rotational operation of which is controlled, wherein

a cleaning mechanism configured for the reaction vessel cleaning is disposed at a predetermined position on the circle of the disk mechanism and a mechanism configured for the optical measurement is disposed at some other position on the circle.

11. The automatic analyzer according to claim 1 , further comprising:

a detergent discharge mechanism including a detergent discharge nozzle configured for discharging a detergent into the reaction vessel and operative to vertically move up and down the detergent discharge nozzle and to discharge the detergent; and

a detergent overflow suction mechanism including a detergent overflow suction nozzle configured for sucking an overflow amount of the detergent in the reaction vessel and operative to vertically move up and down the detergent overflow suction nozzle and to suck the overflow amount of detergent, wherein

in a step using the detergent, the control unit provides control so as to carry out the discharge of the detergent from the detergent discharge nozzle and the suction of the overflow amount of detergent through the detergent overflow suction nozzle when the analyzer is in a second state where a lower end of the detergent discharge nozzle is located at a heightwise third position in the reaction vessel by a downward movement of the detergent discharge mechanism and a lower end of the detergent overflow suction nozzle is located at a heightwise fourth position in the reaction vessel by a downward movement of the detergent overflow suction mechanism, and

a height difference between the first position of the discharge nozzle and the second position of the overflow suction nozzle during the liquid discharge in the liquid discharge step is larger than a height difference between the third position of the detergent discharge nozzle and the fourth position of the detergent overflow suction nozzle during the detergent discharge in the step using the detergent.

12. An automatic analysis method for an automatic analyzer equipped with functions to perform optical measurement and reaction vessel cleaning, wherein

the automatic analyzer comprises:

a control unit configured for controlling a sequence including the optical measurement and the reaction vessel cleaning;

a discharge mechanism including a discharge nozzle configured for discharging a liquid into the reaction vessel and operative to vertically move up and down the discharge nozzle and to discharge the liquid; and

an overflow suction mechanism including an overflow suction nozzle configured for sucking an overflow amount of the liquid in the reaction vessel and operative to vertically move up and down the overflow suction nozzle and to suck the overflow amount of liquid, and

steps performed by the automatic analyzer include:

a step where the control unit operates in a liquid discharge step included in the reaction vessel cleaning preceding the optical measurement and interposed between a preceding step using a detergent and a succeeding blank value measurement step, so as to establish a first state where a lower end of the discharge nozzle is located at a first position in a heightwise lower part of the reaction vessel by a downward movement of the discharge mechanism and a lower end of the overflow suction nozzle is located at a second position in a heightwise upper part of the reaction vessel by a downward movement of the overflow suction mechanism, and

a step where the control unit provides control in the first state so as to carry out the discharge of the liquid from the discharge nozzle and the suction of the overflow amount of liquid through the overflow suction nozzle,

an opening mouth at the lower end of the discharge nozzle has a slant face at a cutting angle of 10 degrees or more, and

the slant face is directed to the overflow suction nozzle as seen from the discharge nozzle.

13. The automatic analysis method according to claim 12 , wherein

the automatic analyzer comprises:

a detergent discharge mechanism including a detergent discharge nozzle configured for discharging a detergent into the reaction vessel and operative to vertically move up and down the detergent discharge nozzle and to discharge the detergent, and

a detergent overflow suction mechanism including a detergent overflow suction nozzle configured for sucking an overflow amount of the detergent in the reaction vessel and operative to vertically move up and down the detergent overflow suction nozzle and to suck the overflow amount of detergent,

a step performed by the automatic analyzer includes a step where the control unit provides control so as to carry out the discharge of the detergent from the detergent discharge nozzle and the suction of the overflow amount of detergent through the detergent overflow suction nozzle in a second state where a lower end of the detergent discharge nozzle is located at a heightwise third position in the reaction vessel by the downward movement of the detergent discharge mechanism and a lower end of the detergent overflow suction nozzle is located at a heightwise fourth position in the reaction vessel, and

a height difference between the first position of the discharge nozzle and the second position of the overflow suction nozzle during the liquid discharge in the liquid discharge step is larger than a height difference between the third position of the detergent discharge nozzle and the fourth position of the detergent overflow suction nozzle during the detergent discharge in the step using the detergent.