Automatic distribution apparatus and method of distribution

• US 6,238,626 B1
• Filed: 04/12/1999
• Issued: 05/29/2001
• Est. Priority Date: 04/13/1998
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Kuroda, Kenichi, Miyazaki, Naoki, Kitahara, Hideyoshi, Daikoku, Takashi, Ishiyama, Kenji, Watanabe, Eiji, Higuchi, Akira, Yahiro, Kanji
• Primary Examiner(s): Warden, Jill
• Assistant Examiner(s): Bex, Keith
• Application Number:
  US09/289,607
• Time in Patent Office: 778 Days
• Field of Search: 422/99, 422/100, 422/104, 422/65, 73/863.01, 73/863.31, 73/863.32, 73/864, 73/864.02, 73/864.24, 73/864.14, 73/864.25, 436/180, 436/47, 141/130
• US Class Current: 422/526
• CPC Class Codes: B01L 3/0275 Interchangeable or disposable dispensing tips
• CPC Class Codes: G01N 2035/103 using disposable tips
• CPC Class Codes: G01N 35/10 Devices for transferring samples or any liquids to, in, or from, the analysis apparatus, e.g. suction devices, injection devices G01N35/0099 takes precedence
• CPC Class Codes: Y10T 436/2575 Volumetric liquid transfer

Abstract

In a method for distributing liquids, in which a distribution tip attached detachably to the lower end of a distribution nozzle can be replaced at any time necessary, a tip rack having a plurality of unused distribution tips lined up thereon is placed on a fitting stage to have the distribution tips fitted with a distribution nozzles. Then, the existence, or non-existence, of a distribution tip left behind on the tip rack without being attached to a distribution nozzle after the fitting operation is finished is detected by a detection section formed of an interrupting-type light sensor, the targeted place of detection by the light sensor being the lower end of the distribution tip. Under the above-described structure, misfitting of a distribution tip can be detected with a high certainty at an early stage before an operation for sucking/discharging liquids is started.

Claims

1. An automatic distribution apparatus for distributing liquids, wherein a distribution tip attached to a lower end of a distribution nozzle can be replaced at any time necessary, comprising:

a fitting stage that supports a tip rack for holding a plurality of unused distribution tips lined up thereon with lower ends of the unused distribution tips projecting downward from a bottom of the tip racks to have the plurality of unused distribution tips fitted with the distribution nozzles; and

a detector for detecting whether or not there is a distribution tip left behind on the tip rack without being attached to one of the distribution nozzles after a fitting operation is finished;

wherein a targeted place of detection by said detector is a portion, of the unused distribution tip left behind on the tip rack, which projects downward from the bottom of the tip rack.

2. The automatic distribution apparatus of claim 1, wherein said detector comprises an optical device for detecting the distribution tip left behind on the tip rack.

3. The automatic distribution apparatus of claim 1, wherein said detector comprises a light sensor having an optical axis in parallel with a direction of the unused distribution tips when lined up on the tip rack.

4. The automatic distribution apparatus of claim 3, further comprising a transfer mechanism for moving the optical axis relative to the tip rack in a direction perpendicular to the optical axis.

5. The automatic distribution apparatus recited in claim 1, wherein said detector has an optical axis arranged below the tip rack.

6. A method of distributing liquids, wherein a distribution tip, which is attached to a lower end of a distribution nozzle, can be replaced at any time necessary, comprising:

placing a tip rack holding a plurality of unused distribution tips lined up thereon with lower ends of the unused distribution tips projecting downward from a bottom of the tip rack;

fitting said plurality of unused distribution tips with said distribution nozzles; and

then detecting whether or not there is a distribution tip left behind on said tip rack without being attached to said distribution nozzle, by detecting a portion, of the distribution tip left behind, which is projecting downward from the bottom of said tip rack.

7. The distribution method recited in claim 6, wherein said detecting comprises optically detecting said distribution tip left behind.

8. The distribution method recited in claim 7, wherein, in optically detecting said distribution tip left behind, a light sensor is arranged with its optical axis in parallel with a direction of the distribution tips lined up on said tip rack.

9. The distribution method recited in claim 8, further comprising shifting a location of said optical axis relative to said tip rack in a direction perpendicular to the optical axis.

10. The distribution method recited in claim 6, further comprising rejecting all of the plurality of unused distribution tips fitted with said distribution nozzles, after detecting the distribution tip left behind on said tip rack.