JP2005003433A

JP2005003433A - Nozzle washing device of liquid dispenser and nozzle washing method

Info

Publication number: JP2005003433A
Application number: JP2003165062A
Authority: JP
Inventors: Shigeru Komiyama; 茂小宮山
Original assignee: Olympus Corp
Current assignee: Olympus Corp
Priority date: 2003-06-10
Filing date: 2003-06-10
Publication date: 2005-01-06

Abstract

<P>PROBLEM TO BE SOLVED: To provide the nozzle washing device of a liquid dispenser constituted so as to stabilize a discharge state by removing the deposit in the vicinity of the nozzle orifice of a nozzle by washing the nozzle having the nozzle orifice for discharging a liquid with droplets of a washing solution, and a nozzle washing method. <P>SOLUTION: The liquid dispenser is constituted so as to discharge the liquid held in a liquid holding member 10 from the nozzle orifice 12 of the nozzle 13 using a liquid discharge head 14 equipped with a liquid holding member 10, a discharge pressure producing means 11 and the nozzle 13 having the nozzle orifice 12. The nozzle discharge device for washing the nozzle 13 of the liquid dispenser is equipped with a washing solution supply means 15 provided at the supply position in the vicinity of the nozzle 13 and forming liquid driplets of the washing solution to supply the same to the nozzle 13 and a washing solution sucking means 16 provided in the suction position in the vicinity of the nozzle 13 to suck the liquid droplets of the washing solution supplied to the nozzle 13 from the washing solution supply means 15. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、液体吐出ヘッドを用いて試料や試薬等の液体を分注する液体分注装置のノズルの洗浄を行う、ノズル洗浄装置およびノズル洗浄方法に関するものである。
【０００２】
【従来の技術】
液体吐出ヘッドを用いて試料や試薬等の液体を分注する液体分注装置としては例えば血液分析機や遺伝子検査、創薬検査等の検査装置がある。これらの装置においては、検査結果の信頼性向上、ランニングコストの削減、スループット向上のために、液体吐出システムの吐出状態の安定化が望まれている。液体吐出システムの吐出状態を安定化する方法としては、液体吐出ヘッドの吐出口近傍の液滴を除去する技術（例えば、特許文献１参照）が提案されている。
【０００３】
この従来技術は、図６に示すプローブ担体製造装置を用いて、液体吐出ヘッドの吐出口近傍の液滴を除去する工程を行うものである。液滴除去工程は、液体吐出ヘッドの吐出口近傍に気体を吹き付ける工程と、吹き付けた気体を液体吐出ヘッドの吐出口近傍で吸引する工程とから成り、図６に示すように、吐出口面２の配列方向とほぼ直交する方向から、気体吹き付け手段４によってプローブ溶液吐出ヘッド１の吐出口面２の近傍に気体５を吹き付け、吹き付けた気体をプローブ溶液吐出ヘッド１の吐出口面２の近傍に設けた吸引手段６によって吸引する。
このようにすることにより、プローブ溶液吐出ヘッド１の吐出口面２の近傍に吹き付けられた気体５は、プローブ溶液の液滴と共に吸引手段によって矢印７で示すように吸引されるため、吐出口面２の近傍に付着した溶液の液滴が除去されるとともに、気体５によって吹き飛ばされた溶液の液滴の四方への飛散が防止されることになる。
【０００４】
【特許文献１】
特開２００２−２８６７３６号公報
【０００５】
【発明が解決しようとする課題】
特許文献１記載のプローブ担体製造装置は、気体を吹き付けることにより液滴を除去するようにしているため、溶液が乾燥しやすくなり、溶液中に溶け込んでいる物質が析出して吐出口の近傍に付着しやすくなる。そして、乾燥した析出物が吐出口に付着した場合、この従来技術では除去することが困難である。
【０００６】
本発明は、液体吐出用の開口を有するノズルを洗浄溶液の液滴で洗浄することにより、開口近傍に付着した不要物を除去して吐出状態を安定化させるようにした液体分注装置のノズル洗浄装置を提供することを第１の目的とする。
本発明は、ノズル洗浄装置を用いて液体吐出用の開口を有するノズルを洗浄溶液の液滴で洗浄することにより、開口近傍に付着した不要物を除去して吐出状態を安定化させるようにした液体分注装置のノズル洗浄方法を提供することを第２の目的とする。
【０００７】
【課題を解決するための手段】
上記第１の目的を達成するため、請求項１に記載の第１発明は、内部に液体を保持する液体保持部材と、液体吐出用の開口を有するノズルとを備える液体吐出ヘッドを用いて、前記ノズルの開口から前記液体保持部材内に保持された液体を吐出する液体分注装置において、前記ノズルの洗浄を行うノズル洗浄装置であって、前記ノズルの近傍の供給位置に設けられ、洗浄溶液の液滴を形成して前記ノズルに供給する洗浄溶液供給手段と、前記ノズルの近傍の吸引位置に設けられ、前記洗浄溶液供給手段から前記ノズルに供給される洗浄溶液の液滴を吸引する洗浄溶液吸引手段とを具備して成ることを特徴とする。
【０００８】
第１発明においては、液体分注装置の液体吐出ヘッドの液体吐出用の開口を有するノズルを洗浄する際には、前記ノズルの近傍の供給位置に設けられた洗浄溶液供給手段によって形成した洗浄溶液の液滴を前記ノズルに供給し、前記ノズルの近傍の吸引位置に設けられた洗浄溶液吸引手段によって、前記洗浄溶液供給手段から前記ノズルに供給される洗浄溶液の液滴を吸引する。
第１発明によれば、洗浄溶液供給手段によって液体吐出用の開口を有するノズルに洗浄溶液の液滴を供給し、該ノズルに付着した洗浄溶液の液滴を洗浄溶液吸引手段によって吸引する湿式洗浄方式を採用したので、液体吐出用の開口を有するノズルは洗浄中は洗浄溶液の液滴で湿った状態となる。したがって、乾式洗浄方式を用いる上記従来技術のように溶液中に溶け込んでいる物質が析出物として液体吐出用の開口付近に付着することはほとんどなく、液体吐出用の開口付近に付着するものは不要な液体（例えば分注後に残留した試料や試薬等の液体）であり、この不要な液体も洗浄溶液吸引手段による吸引によって除去されるので、ノズルの液体吐出用の開口近傍には吐出状態を不安定にする物質は全く存在しなくなり、吐出状態を安定化させることができる。
【０００９】
請求項２に記載の第２発明は、前記ノズルから液体吐出方向に所定距離離間した回収位置に、液体を回収する液体回収槽を設けて成ることを特徴とする。
【００１０】
第２発明によれば、前記ノズルから液体吐出方向に所定距離離間した回収位置には、液体を回収する液体回収槽が設けられているので、前記ノズルに付着してノズル外周部および液体吐出用の開口に付着した残留液体を吸収した洗浄溶液の液滴が洗浄溶液吸引手段によって吸引しきれずにノズルから落下した場合に液体回収槽に回収されることになり、落下した洗浄溶液の液滴によって液体分注装置が汚染されることを防止することができる。
【００１１】
請求項３に記載の第３発明は、前記洗浄溶液供給手段は、複数種類の洗浄溶液の何れか１つを選択的に導入する洗浄溶液導入手段を備えることを特徴とする。
【００１２】
第３発明によれば、前記洗浄溶液供給手段は複数種類の洗浄溶液の何れか１つを選択的に導入する洗浄溶液導入手段を備えているので、１種類の洗浄溶液では所望の洗浄効果が期待できないようなノズルの汚染に対しては、使用する洗浄溶液を切り換えることにより複数種類の洗浄溶液を用いてノズルを洗浄することが可能になり、所望の洗浄効果を得ることができる。
【００１３】
請求項４に記載の第４発明は、前記洗浄溶液供給手段および前記洗浄溶液吸引手段をそれぞれ複数設けるとともに、何れか１つの洗浄溶液吸引手段により選択的に吸引された洗浄溶液を廃液する廃液手段を設けて成ることを特徴とする。
【００１４】
第４発明によれば、前記洗浄溶液供給手段および前記洗浄溶液吸引手段をそれぞれ複数設けるとともに何れか１つの洗浄溶液吸引手段により吸引された洗浄溶液を選択的に廃液する廃液手段を設けるようにしたので、１種類の洗浄溶液では所望の洗浄効果が期待できないようなノズルの汚染に対しては、複数系統の洗浄溶液供給手段および洗浄溶液吸引手段によって複数種類の洗浄溶液を用いてノズルを洗浄することが可能になり、所望の洗浄効果を得ることができる。さらに、複数の洗浄溶液供給手段を用いて複数種類の洗浄溶液を前記ノズルの異なる部位に供給することができ、また、何れか１つの洗浄溶液吸引手段により吸引された洗浄溶液を選択的に廃液することでノズル上の洗浄溶液液滴の通過経路を選択することができるので、１組の洗浄溶液供給手段および洗浄溶液吸引手段を用いる場合に比べてノズルの洗浄可能範囲が拡大され、洗浄効果が増大する。
【００１５】
請求項５に記載の第５発明は、前記洗浄溶液供給手段を複数設けるとともに、該複数の洗浄溶液供給手段に対して少なくとも１つの洗浄溶液吸引手段を共通設置するようにしたことを特徴とする。
【００１６】
第５発明によれば、前記洗浄溶液供給手段を複数設けるとともに、該複数の洗浄溶液供給手段に対して少なくとも１つの洗浄溶液吸引手段を共通設置するようにしたので、１種類の洗浄溶液では所望の洗浄効果が期待できないようなノズルの汚染に対しては、前記複数の洗浄溶液供給手段から複数種類の洗浄溶液を順次または同時に供給して共通設置された少なくとも１つの洗浄溶液吸引手段で吸引することによって順次または同時に複数種類の洗浄溶液を用いてノズルを洗浄することが可能になり、所望の洗浄効果を得ることができる。さらに、複数の洗浄溶液供給手段を用いて前記ノズルの異なる部位に順次または同時に複数種類の洗浄溶液を供給することができるので、１組の浄溶液供給手段および洗浄溶液吸引手段を用いる場合に比べてノズルの洗浄可能範囲が大幅に拡大されることになり、洗浄効果がさらに増大する。
【００１７】
請求項６に記載の第６発明は、少なくとも１つ以上の前記洗浄溶液供給手段を前記ノズルの開口よりも上方に配置して成ることを特徴とする。
【００１８】
第６発明によれば、少なくとも１つ以上の前記洗浄溶液供給手段は前記ノズルの開口よりも上方に配置されているので、その洗浄溶液供給手段によってノズルの側面部や開口に液滴を付着させることが可能になり、ノズルの開口ばかりでなく、ノズルの側面部の洗浄も行うことができるようになる。
【００１９】
上記第２の目的を達成するため、請求項７に記載の第７発明は、第１発明〜第６発明の何れかの液体分注装置のノズル洗浄装置を用いてノズルの洗浄を行うノズル洗浄方法であって、洗浄溶液の液滴を前記ノズルに供給して付着させるとともに、該ノズルに付着した洗浄溶液の液滴を吸引することにより、前記ノズルの洗浄を行うことを特徴とする。
【００２０】
第７発明によれば、第１発明〜第６発明の何れかの液体分注装置のノズル洗浄装置を用いてノズルの洗浄を行う際に、洗浄溶液の液滴を前記ノズルに供給して付着させるとともに該ノズルに付着した洗浄溶液の液滴を吸引することにより前記ノズルの洗浄を行うので、第１発明と同様の作用効果を得ることができる。
【００２１】
請求項８に記載の第８発明は、複数種類の洗浄溶液を用いて前記ノズルの洗浄を行うことを特徴とする。
【００２２】
第８発明によれば、複数種類の洗浄溶液を用いて前記ノズルの洗浄を行う（第３発明のノズル洗浄装置の場合には複数種類の洗浄溶液を切り換えて前記ノズルを洗浄し、第４発明のノズル洗浄装置の場合には複数種類の洗浄溶液を用いて前記ノズルを洗浄し、第５発明のノズル洗浄装置の場合には複数の洗浄溶液供給手段から順次または同時に供給する複数種類の洗浄溶液を用いて前記ノズルを洗浄する）から、第３発明〜第５発明と同様の作用効果を得ることができる。
【００２３】
【発明の実施の形態】
以下、本発明の実施の形態を図面に基づき詳細に説明する。図１は本発明の第１実施形態の液体分注装置のノズル洗浄装置の要部の構成を示す図である。本実施形態の液体分注装置のノズル洗浄装置は、内部に液体を保持する液体保持部材１０と、液体保持部材１０の上部を固定支持する吐出圧力発生手段１１と、液体吐出用の開口であるノズル口１２を有するノズル１３とを備える液体吐出ヘッド１４を用いて、ノズル１３のノズル口１２から液体保持部材１０内に保持された液体を吐出する液体分注装置において、ノズル１３の洗浄を行うものであり、ノズル１３の近傍の供給位置に設けられ、洗浄溶液の液滴を形成してノズル１３に供給する洗浄溶液供給手段１５と、ノズル１３の近傍の吸引位置に設けられ、洗浄溶液供給手段１５からノズル１３に供給される洗浄溶液の液滴を吸引する洗浄溶液吸引手段１６等を具備して成る。
【００２４】
液体保持部材１０は、配管１８により、図示しない液体供給系に接続されている。前記液体供給系は、例えば、配管１８側から、シリンジピストンポンプ、電磁弁、送水ポンプ、液体供給タンクを順次接続することにより構成するものとする。液体保持部材１０への液体（吐出溶液）の供給は、シリンジポンプによる吸引または液体供給タンクから送水ポンプによる送水によって行う。
【００２５】
液体吐出ヘッド１４は、図示しない搬送装置に支持されており、図１に示す溶液回収槽１７の上方と、図示しない液体吐出容器の上方との間を移動可能に配置されている。溶液回収槽１７は、ノズル１０から液体吐出方向（図１の場合、直下方向）に所定距離離間した回収位置に配置されている。なお、本実施形態のノズル洗浄装置では、ノズル１３の外周およびノズル口１２の洗浄を行うが、それとは別途に、液体保持部材１０およびノズル１３の内部流路の洗浄を行うように構成されているため、溶液回収槽１７は、液体保持部材１０およびノズル１３の内部流路に流された洗浄溶液を回収する洗浄溶液回収槽を兼用している。
【００２６】
洗浄溶液供給手段１５および洗浄溶液吸引手段１６は、例えば内径φ＝０．０５〜２ｍｍのステンレス製の細管により構成されている。洗浄溶液供給手段１５および洗浄溶液吸引手段１６はそれぞれ、溶液回収槽１７の真上に設けられた洗浄位置に移動した液体吐出ヘッド１４のノズル１３のノズル口１２近傍の供給位置および吸引位置に、図示のように設置されている。
【００２７】
洗浄溶液供給手段１５は、複数種類（図示例では２種類）の洗浄溶液の何れか１つを選択的に導入する洗浄溶液導入手段を備えている。洗浄溶液導入手段は、図示しない２つの洗浄溶液タンクから図示しない送水ポンプによって図示矢印のように送液される洗浄溶液１９，２０を導く送水配管２１，２２と、送水配管２１，２２の何れか一方を、洗浄溶液供給手段１５に接続された送水配管２３に接続する切換弁（供給経路切換手段）２４とから成る。本実施形態では、切換弁２４への送水経路が２系統設けられており、各送水経路はそれぞれ異なる洗浄溶液を矢印１９，２０で示すように洗浄溶液供給手段１５側に送水することができる。すなわち、矢印１９側から送水する場合には切換弁２４が送水配管２１側へ切り換わり、矢印２０側から送水する場合には切換弁２４が送水配管２２側へ切り換わるように構成されている。
【００２８】
洗浄溶液吸引手段１６は、廃液回収槽２５を介して図示しない吸引ポンプに接続されており、吸引ポンプを駆動することにより、矢印２６で示す方向にノズル１３に供給される洗浄溶液の液滴を吸引して、廃液回収槽２５に洗浄溶液の液滴を廃液として回収するように構成されている。
【００２９】
次に、本実施形態の液体分注装置のノズル洗浄装置によるノズル洗浄動作について図２を用いて説明する。図２は第１実施形態における洗浄時のノズル１３の先端部の液滴の移動状態を示す図であり、ノズル１３の先端部に形成されたノズル口１２は、ノズル１３内の流路および液体保持部材１０内の流路（何れも図示せず）を介して配管１８に連通している。本実施形態においては、洗浄溶液供給手段１５とノズル１３の先端部側面との間の距離は、洗浄溶液供給手段１５によって形成される液滴（例えば図２の液滴２７）がノズル１３に付着し得るような範囲内の距離であればよく、例えば０．１〜３ｍｍに設定するものとする。また、ノズル１３の先端部側面と洗浄溶液吸引手段１６との間の距離は、洗浄溶液吸引手段１６によってノズル１３に付着した液滴（例えば図２の液滴２８）を吸引し得るような範囲内の距離であればよく、例えば０．１〜１０ｍｍに設定するものとする。
【００３０】
ノズル１３を洗浄する際には、事前に、液体吐出ヘッド１４を図示しない搬送装置によって溶液回収槽１７の上方の洗浄位置に移動させて図１に示す状態にしておくものとする。
この状態において洗浄動作を開始する際には、切換弁２４によって１種類目の洗浄溶液として例えば洗浄溶液１９を選択することにより、送水配管２１に接続された図示しない送水ポンプによって洗浄溶液１９が徐々に送液され、送水配管２１、切換弁２４および送水配管２３を経て洗浄溶液供給手段１５に洗浄溶液１９が導入され、ノズル１３の洗浄に供されることになる。
【００３１】
次に、切換弁２４によって２種類目の洗浄溶液として洗浄溶液２０を選択する。これにより、送水配管２２に接続された図示しない送水ポンプによって洗浄溶液２０が徐々に送液され、送水配管２２、切換弁２４および送水配管２３を経て洗浄溶液供給手段１５に洗浄溶液２０が導入され、ノズル１３の洗浄に供されることになる。
【００３２】
上記ノズル洗浄時には、ノズル１３の先端部における液滴の動きは図２に示すようになる。すなわち、洗浄溶液供給手段１５から洗浄溶液１９，２０をノズル１３に供給する際には、洗浄溶液供給手段１５がノズル１３の先端の近傍に配置されているので、ノズル１３の先端部の洗浄溶液供給手段１５寄りの部位には、図示のように洗浄溶液１９，２０の液滴２７が付着することになる。
【００３３】
一方、図示しない吸引ポンプに接続された洗浄溶液吸引手段１６によって液滴を吸引する際には、吸引ポンプの駆動に伴い気流が生じる。ノズル１３に付着した液滴２７は、前記気流によって、ノズル１３の先端部を図２に矢印２９で示す方向に移動する。先端部を移動した液滴２７は、液滴２８で示すように、図２に矢印３０で示す方向へ移動して、気流とともに洗浄溶液吸引手段１６へと吸い込まれる。吸い込まれた液滴２８は、図１に示す廃液回収槽２５によって回収される。なお、洗浄溶液吸引手段１６で吸引しきれずにノズル１３から落下した洗浄溶液の液滴は溶液回収槽１７に回収されるので、落下した洗浄溶液の液滴によって液体分注装置が汚染されることが防止される。
【００３４】
本実施形態のノズル洗浄装置によれば、洗浄溶液供給手段１５によってノズル口１２を有するノズル１３に洗浄溶液の液滴を供給し、ノズル１３に付着した洗浄溶液の液滴を洗浄溶液吸引手段１６によって吸引する湿式洗浄方式を採用したので、ノズル口１２を有するノズル１３は洗浄中は洗浄溶液の液滴で湿った状態となり、乾式洗浄方式を用いる上記従来技術のように溶液中に溶け込んでいる物質が析出物としてノズル口付近に付着することはほとんどなく、ノズル口付近に付着するものは不要な液体（例えば分注後に残留した試料や試薬等の液体）であり、この不要な液体も洗浄溶液吸引手段１６による吸引によって除去されるので、ノズル１３のノズル口１２の近傍には吐出状態を不安定にする物質は全く存在しなくなり、吐出状態を安定化させることができる。
【００３５】
また、本実施形態のノズル洗浄装置によれば、洗浄溶液の液滴の供給および吸引を繰り返す上記洗浄動作時の洗浄条件を以下のように設定することにより、洗浄条件に応じた洗浄効果が得られる。
［洗浄条件１］
洗浄溶液供給手段１５で洗浄溶液の液滴を１秒間に数滴形成してノズル１３に供給するとともに、供給と同時に洗浄溶液吸引手段１６で洗浄溶液の液滴を吸引するように洗浄条件を設定した場合、洗浄溶液の液滴の供給と吸引とが繰り返され、ノズル１３の先端部を洗浄溶液の液滴２７，２８がそれぞれ矢印２９，３０方向に次々と通過するので、液体吐出ヘッド１４のノズル１３の外周部およびノズル口１２の近傍に付着物が存在する場合であっても、その付着物を洗い流すことができる。
【００３６】
［洗浄条件２］
洗浄溶液供給手段１５で洗浄溶液の液滴を１秒間に１滴程度で連続的に数滴形成してノズル１３に供給するとともに、供給と同時に洗浄溶液吸引手段１６で洗浄溶液の液滴を吸引するように洗浄条件を設定した場合、液滴２７は、液体吐出ヘッド１４のノズル口１２を通過する際に、ノズル口１２に満たされている吐出溶液の表面に水分を供給（補給）することになる。そのため、ノズル口１２内の吐出溶液の表面が、乾燥に起因して、粘度が高くなったり、固まったりして、吐出溶液の吐出状態が不安定となっていた場合であっても、上記水分の補給により、吐出溶液表面の粘度を徐々に低下させたり、固まった溶液表面を徐々に溶解したりして、吐出状態を所望の状態に復元させることができる。
【００３７】
［洗浄条件３］
洗浄溶液供給手段１５から供給する液滴２７がノズル１３の先端部を包むような状態で液滴２７を付着させた後、ノズル１３の外周部およびノズル口１２の周辺の付着物（残留液体等）が液滴２７に溶解されるまで一定時間放置し、その後、洗浄溶液吸引手段１６で洗浄溶液の液滴を吸引するように洗浄条件を設定した場合、ノズル口１２内の吐出溶液の表面が固まって吐出しない状態となった場合であっても、固まった溶液表面を時間をかけて溶解して、吐出状態を所望の状態に復元させることができる。
【００３８】
また、本実施形態のノズル洗浄装置によれば、洗浄溶液供給手段１５は複数種類（図１の場合、２種類）の洗浄溶液の何れか１つを選択的に導入する切換弁２４を備えているので、１種類の洗浄溶液では所望の洗浄効果が期待できないようなノズルの汚染に対しては、使用する洗浄溶液を切り換えることにより複数種類（図１の場合、２種類）の洗浄溶液を用いてノズルを洗浄することが可能になり、所望の洗浄効果を得ることができる。
【００３９】
以下に、汚染に応じた２種類の洗浄溶液の好適な組み合わせを例示する。
第１の洗浄溶液として水を用いただけでは所望の洗浄効果が期待できないときには、第２の洗浄溶液として、例えば、洗浄すべき吐出溶液に油脂類が含まれている場合には界面活性剤を用い、洗浄すべき吐出溶液に血液のような体液が含まれている場合にはバッファーを用い、洗浄すべき吐出溶液にＤＮＡのような極性を持った物質が含まれている場合には酸やアルカリ溶液等を用いるように、上記各種洗浄溶液を用意しておくことにより、ノズルの洗浄を確実に行うことができる。あるいは、大腸菌のような細菌を含む溶液を吐出した場合には、消毒液を用意しておくことにより、ノズル１２の先端の殺菌を行うこともできる。
【００４０】
さらに、本実施形態のノズル洗浄装置は、流水ではなく、液滴によって洗浄を行うように構成したため、廃液量を減少させることができ、生体試料や細菌、毒物等の吐出を行った場合であってもそれらが含まれた厳密な処理が必要な廃液の発生を少量にすることができ、コスト、環境面で負荷を減らすことができる。
【００４１】
図３は本発明の第２実施形態の液体分注装置のノズル洗浄装置の要部の構成を示す図である。本実施形態の液体分注装置のノズル洗浄装置は、上記第１実施形態に対し、洗浄溶液供給手段および洗浄溶液吸引手段を複数組（本実施形態の場合、２組）設けるとともに、何れか１つの洗浄溶液吸引手段により選択的に吸引された洗浄溶液を廃液する廃液手段を設ける変更を加えたものである。
【００４２】
すなわち、本実施形態のノズル洗浄装置は、図３に示すように、液体吐出ヘッド１４のノズル１３の近傍の第１供給位置に設けられ、第１の洗浄溶液３１の液滴を形成して矢印３２で示すようにノズル１３に供給する洗浄溶液供給手段３３と、ノズル１３の近傍の第１吸引位置に設けられ、洗浄溶液供給手段３３からノズル１３に供給される第１の洗浄溶液３１の液滴を吸引する洗浄溶液吸引手段３４と、ノズル１３の近傍の第２供給位置に設けられ、第２の洗浄溶液３５の液滴を形成して矢印３６で示すようにノズル１３に供給する洗浄溶液供給手段３７と、ノズル１３の近傍の第２吸引位置に設けられ、洗浄溶液供給手段３７からノズル１３に供給される第２の洗浄溶液３５の液滴を吸引する洗浄溶液吸引手段３８と、洗浄溶液吸引手段３７，３８の何れか一方により選択的に吸引された洗浄溶液を廃液回収槽２５に廃液するために流路を切り換える切換弁（吸引経路切換手段）３９等を具備して成る。なお、図３には、洗浄溶液供給手段３３，３７および洗浄溶液吸引手段３４，３８を液体吐出ヘッド１４に対し斜め方向に表わしたが、実際には、洗浄溶液供給手段３３，３７および洗浄溶液吸引手段３４，３８は、上記第１実施形態と同様に液体吐出ヘッド１４のノズル１３の先端部近傍の同一水平面上に設定された第１供給位置、第２供給位置、第１吸引位置、第２吸引位置に配置されており、２組の洗浄溶液供給手段および洗浄溶液吸引手段は互いに直交するように配置されている。
【００４３】
洗浄溶液供給手段３３、３７はそれぞれ、図示しない異なる洗浄溶液送水ポンプを介して種類の異なる洗浄溶液が入った洗浄溶液タンクに接続されている。洗浄溶液供給手段３３から第１の洗浄溶液３１の液滴を供給する場合には、洗浄溶液供給手段３３に接続された洗浄溶液送水ポンプ駆動することにより矢印３１で示す方向に洗浄溶液３１が送水され、洗浄溶液供給手段３７から洗浄溶液３５の液滴を供給する場合には、洗浄溶液供給手段３７に接続された洗浄溶液送水ポンプを駆動することにより矢印３５で示す方向に洗浄溶液３５が送水されるようになっている。
【００４４】
次に、本実施形態の液体分注装置のノズル洗浄装置によるノズル洗浄動作について図４を用いて説明する。なお、ノズル１３を洗浄する際には、事前に、液体吐出ヘッド１４を図示しない搬送装置によって溶液回収槽１７の上方の洗浄位置に移動させて図３に示す状態にしておくものとする。
洗浄のために第１の洗浄溶液３１を選択した場合には、図示しない洗浄溶液送水ポンプを駆動することにより洗浄溶液３１が徐々に送り出され、洗浄溶液供給手段３３に導入される。一方、洗浄のために第２の洗浄溶液３５を選択した場合には、図示しない洗浄溶液送水ポンプを駆動することにより洗浄溶液３５が徐々に送り出され、洗浄溶液供給手段３７に導入される。
【００４５】
上記ノズル洗浄時には、ノズル１３の先端部における液滴の動きは図４に示すようになる。図４は第２実施形態における洗浄時のノズル１３の先端部の液滴の移動状態を示す図であり、ノズル１３を真下から見上げた状態を表わしている。洗浄溶液供給手段３３，３７および洗浄溶液吸引手段３４，３８が液体吐出ヘッド１４のノズル１３の先端部近傍に配置されているため、第１の洗浄溶液３１を導く経路が選択されている場合に導かれる第１の洗浄溶液３１は、洗浄溶液供給手段３３の先端に液滴４０を形成し、形成された液滴４０は図示のようにノズル１３に付着する。同様に、第２の洗浄溶液３５を導く経路が選択されている場合に導かれる第２の洗浄溶液３５は、洗浄溶液供給手段３７の先端に液滴４１を形成し、形成された液滴４１は図示のようにノズル１３に付着する。
【００４６】
一方、図示しない吸引ポンプに接続された洗浄溶液吸引手段３４，３８によって液滴を吸引する際には、上記第１実施形態と同様に吸引ポンプの駆動に伴い気流が生じる。それにより、ノズル１３に付着した液滴４０，４１はそれぞれ、前記気流によって、ノズル１３のノズル口１２が形成された先端面４２を図４に矢印３２，３６で示す方向に移動する。先端面４２を移動した液滴４０，４１はそれぞれ、気流とともに洗浄溶液吸引手段３４，３８へと吸い込まれる。吸い込まれた液滴は、図３に示す廃液回収槽２５によって回収される。なお、洗浄溶液吸引手段３４，３８で吸引しきれずにノズル１３から落下した洗浄溶液の液滴は溶液回収槽１７に回収されるので、落下した洗浄溶液の液滴によって液体分注装置が汚染されることが防止される。
【００４７】
本実施形態のノズル洗浄装置によれば、洗浄溶液供給手段３３，３７によってノズル口１２を有するノズル１３に洗浄溶液の液滴４０，４１を選択的に供給し、ノズル１３に付着した洗浄溶液の液滴４０，４１を洗浄溶液吸引手段３４，３８によって選択的に吸引する湿式洗浄方式を採用したので、ノズル口１２を有するノズル１３は洗浄中は洗浄溶液の液滴で湿った状態となり、乾式洗浄方式を用いる上記従来技術のように溶液中に溶け込んでいる物質が析出物としてノズル口付近に付着することはほとんどなく、ノズル口付近に付着するものは不要な液体（例えば分注後に残留した試料や試薬等の液体）であり、この不要な液体も洗浄溶液吸引手段３４，３８による選択的な吸引によって除去されるので、ノズル１３のノズル口１２の近傍には吐出状態を不安定にする物質は全く存在しなくなり、吐出状態を安定化させることができる。
【００４８】
また、本実施形態のノズル洗浄装置によれば、洗浄溶液の液滴の供給および吸引を繰り返す上記洗浄動作時の洗浄条件を例えば第１実施形態と同様に設定することにより、第１実施形態と同様に洗浄条件に応じた洗浄効果が得られる。
さらに、本実施形態のノズル洗浄装置によれば、２つの洗浄溶液供給手段を用いて２種類の洗浄溶液をノズル１３の異なる部位に供給してノズルを洗浄する構成としたため、１組の浄溶液供給手段および洗浄溶液吸引手段を用いる場合に比べてノズルの洗浄可能範囲が拡大されることになり、ノズル１３の先端面４２の洗浄を希望する部位を洗浄溶液が通過するように、吸引経路切換手段３９を切り換えることによって洗浄溶液の経路を選択することが可能になり、確実にノズル口１２の周辺の付着物を洗い流すことができるようになるので、洗浄効果が増大する。
【００４９】
なお、上記第２実施形態では、洗浄溶液供給手段および洗浄溶液吸引手段を２組用いたが、浄溶液供給手段および洗浄溶液吸引手段が対をなす必要はなく、複数の洗浄溶液供給手段および少なくとも１つの洗浄溶液吸引手段を用いたり、あるいは、少なくとも１つの洗浄溶液供給手段および複数の洗浄溶液吸引手段を用いたりしてもよい。
【００５０】
図５は本発明の第３実施形態の液体分注装置のノズル洗浄装置の要部の構成を示す図である。本実施形態の液体分注装置のノズル洗浄装置は、上記第１実施形態に対し、洗浄溶液供給手段を複数（この場合、４つ）設けて、複数の洗浄溶液供給手段に対して少なくとも１つ（この場合、１つ）の洗浄溶液吸引手段を共通設置するとともに、少なくとも１つ以上の洗浄溶液供給手段をノズル１３のノズル口１２よりも上方に配置する変更を加えたものである。
【００５１】
すなわち、本実施形態のノズル洗浄装置においては、図５に示すように、液体吐出ヘッド１４のノズル１３の近傍の第１吸引位置〜第４吸引位置にはそれぞれ洗浄溶液供給手段５１〜５４が設けられており、ノズル１３の近傍の共通吸引位置には洗浄溶液吸引手段５５が設けられている。図示例では、洗浄溶液供給手段５１〜５４の全てがノズル口１２よりも上方に配置されており、洗浄溶液吸引手段５５は、その吸引側端部がノズル口１２の下方に配置されるようになっている。洗浄溶液供給手段５１〜５４は、図示しない洗浄溶液送水ポンプを介して洗浄溶液が入った洗浄溶液タンクに接続されており、洗浄溶液吸引手段５５は、第１実施形態と同様に、図示しない廃液回収槽を介して図示しない吸引ポンプに接続されている。なお、洗浄溶液供給手段５１〜５４は、図示しない異なる洗浄溶液送水ポンプを介して異なる洗浄溶液（この場合、最大４種類の洗浄溶液、少なくとも２種類の洗浄溶液）が入った複数の洗浄溶液タンクに接続されていても良い。
【００５２】
上記において、洗浄溶液吸引手段５５の吸引側端部を設ける位置は、各洗浄溶液供給手段に対して均等に吸引するためにはノズル口１２の直下が望ましいが、ノズル口１２の直下に設けた場合には、液体保持部材１０およびノズル１３の内部流路の洗浄のための洗浄溶液が落下する際に支障するおそれがあるので、直下から若干ずれた位置に設けるものとする。また、洗浄溶液吸引手段５５の設置角度は、図示例では水平に近い角度としているが、垂直に近い角度としてもよい。また、洗浄溶液吸引手段５５の径を洗浄溶液供給手段５１〜５４の径よりも大きくすることが、４つの洗浄溶液供給手段５１〜５４から供給される洗浄溶液の液滴を吸引する上で好ましい。
【００５３】
次に、本実施形態の液体分注装置のノズル洗浄装置によるノズル洗浄動作について図５を用いて説明する。なお、ノズル１３を洗浄する際には、事前に、液体吐出ヘッド１４を図示しない搬送装置によって図示しない溶液回収槽の上方の洗浄位置に移動させて図５に示す状態にしておくものとする。
図示しない洗浄溶液送水ポンプを駆動することにより、洗浄溶液が徐々に送り出され、洗浄溶液供給手段５１〜５４に導入される。洗浄溶液供給手段５１〜５４および洗浄溶液吸引手段５５が液体吐出ヘッド１４のノズル１３の先端部近傍に配置されているため、導入された洗浄溶液は、図５に示すように、洗浄溶液供給手段５１〜５４の先端に洗浄溶液の液滴５６〜５９となって付着する。
【００５４】
ここで、図示しない吸引ポンプを駆動することにより洗浄溶液吸引手段５５によって吸引に伴う気流が生じる。ノズル１３に付着した液滴５６〜５９は、この気流と液滴の自重による下方向への移動とによって、ノズル１３の側面ならびに先端部を矢印６０で示すように移動して、気流とともに洗浄溶液吸引手段５９へと吸い込まれる。吸い込まれた液滴は、第１実施形態と同様に、廃液回収槽によって回収される。なお、洗浄溶液吸引手段５９で吸引しきれずにノズル１３から落下した洗浄溶液の液滴は、これも第１実施形態と同様に溶液回収槽に回収されるので、落下した洗浄溶液の液滴によって液体分注装置が汚染されることが防止される。
【００５５】
本実施形態のノズル洗浄装置によれば、洗浄溶液供給手段５１〜５４によってノズル口１２を有するノズル１３に洗浄溶液の液滴５６〜５９を供給し、ノズル１３に付着した洗浄溶液の液滴５６〜５９を洗浄溶液吸引手段５５によって共通に吸引する湿式洗浄方式を採用したので、ノズル口１２を有するノズル１３は洗浄中は洗浄溶液の液滴で湿った状態となり、乾式洗浄方式を用いる上記従来技術のように溶液中に溶け込んでいる物質が析出物としてノズル口付近に付着することはほとんどなく、ノズル口付近に付着するものは不要な液体（例えば分注後に残留した試料や試薬等の液体）であり、この不要な液体も洗浄溶液吸引手段５５による吸引によって除去されるので、ノズル１３のノズル口１２の近傍には吐出状態を不安定にする物質は全く存在しなくなり、吐出状態を安定化させることができる。
【００５６】
また、本実施形態のノズル洗浄装置によれば、洗浄溶液の液滴の供給および吸引を繰り返す上記洗浄動作時の洗浄条件を例えば第１実施形態と同様に設定することにより、第１実施形態と同様に洗浄条件に応じた洗浄効果が得られる。
さらに、本実施形態のノズル洗浄装置によれば、４つの浄溶液供給手段および１つの共通の洗浄溶液吸引手段５５を用いてノズル１３の異なる部位に順次または同時に複数種類の洗浄溶液を供給することができる構成としたため、１組の浄溶液供給手段および洗浄溶液吸引手段を用いる場合に比べてノズルの洗浄可能範囲が大幅に拡大されることになり、ノズル１３の側面部や先端部の洗浄を希望する部位を洗浄溶液が通過するように洗浄溶液の経路を選択することが可能になり、確実にノズル１３の側面部やノズル口１２の周辺の付着物を洗い流すことができるようになるので、洗浄効果がさらに増大する。
【００５７】
なお、上記第３実施形態では、複数（４つ）の洗浄溶液供給手段および１つの洗浄溶液吸引手段を用いたが、少なくとも１つの洗浄溶液供給手段および複数の洗浄溶液吸引手段を用いるようにしてもよい。また、上記第１実施形態と同様に、洗浄溶液供給手段に、複数種類の洗浄溶液の何れか１つを選択的に導入する洗浄溶液導入手段を設けるようにしてもよい。さらに、本実施形態において複数の洗浄溶液吸引手段を設ける構成とした場合には、上記第２実施形態と同様に、洗浄溶液吸引手段に電磁弁（段吸引経路切換手段）を設けるようにしてもよい。
【図面の簡単な説明】
【図１】本発明の第１実施形態の液体分注装置のノズル洗浄装置の要部の構成を示す図である。
【図２】第１実施形態の液体分注装置のノズル洗浄装置によるノズル洗浄動作を説明するための図である。
【図３】本発明の第２実施形態の液体分注装置のノズル洗浄装置の要部の構成を示す図である。
【図４】第２実施形態の液体分注装置のノズル洗浄装置によるノズル洗浄動作を説明するための図である。
【図５】本発明の第３実施形態の液体分注装置のノズル洗浄装置の要部の構成ならびにノズル洗浄動作を説明するための図である。
【図６】従来技術を説明するための図である。
【符号の説明】
１０液体保持部材
１１吐出圧力発生手段
１２ノズル口（液体吐出用の開口）
１３ノズル
１４液体吐出ヘッド
１５洗浄溶液供給手段
１６洗浄溶液吸引手段
１７溶液回収槽
１８配管
１９，２０洗浄溶液（洗浄溶液の流れを示す矢印）
２１、２２，２３配管
２４切換弁（供給経路切換手段）
２５廃液回収槽
２６廃液（廃液の流れを示す矢印）[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a nozzle cleaning apparatus and a nozzle cleaning method for cleaning a nozzle of a liquid dispensing apparatus that dispenses a liquid such as a sample or a reagent using a liquid discharge head.
[0002]
[Prior art]
Examples of liquid dispensing devices that dispense liquids such as samples and reagents using a liquid discharge head include blood analyzers, genetic testing, drug testing, and other testing devices. In these apparatuses, it is desired to stabilize the discharge state of the liquid discharge system in order to improve the reliability of the inspection result, reduce the running cost, and improve the throughput. As a method for stabilizing the discharge state of the liquid discharge system, a technique for removing droplets in the vicinity of the discharge port of the liquid discharge head (for example, see Patent Document 1) has been proposed.
[0003]
This prior art performs a step of removing droplets in the vicinity of the discharge port of the liquid discharge head using the probe carrier manufacturing apparatus shown in FIG. The droplet removing step includes a step of blowing a gas near the discharge port of the liquid discharge head and a step of sucking the sprayed gas near the discharge port of the liquid discharge head. As shown in FIG. From the direction substantially orthogonal to the arrangement direction of the gas, the gas blowing means 4 blows the gas 5 in the vicinity of the discharge port surface 2 of the probe solution discharge head 1, and the blown gas is brought in the vicinity of the discharge port surface 2 of the probe solution discharge head 1. Suction is performed by the provided suction means 6.
By doing so, the gas 5 blown in the vicinity of the discharge port surface 2 of the probe solution discharge head 1 is sucked together with the probe solution droplets by the suction means as indicated by the arrow 7. The droplets of the solution adhering to the vicinity of 2 are removed, and the droplets of the solution blown off by the gas 5 are prevented from being scattered in all directions.
[0004]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 2002-286736
[0005]
[Problems to be solved by the invention]
In the probe carrier manufacturing apparatus described in Patent Document 1, since the droplets are removed by blowing the gas, the solution is easily dried, and the substance dissolved in the solution is precipitated and is near the discharge port. It becomes easy to adhere. And when the dried deposit adheres to a discharge outlet, it is difficult to remove by this prior art.
[0006]
The present invention relates to a nozzle for a liquid dispensing device in which a nozzle having a liquid discharge opening is cleaned with a droplet of a cleaning solution to remove unnecessary substances attached in the vicinity of the opening and stabilize the discharge state. It is a first object to provide a cleaning device.
In the present invention, a nozzle having a liquid discharge opening is cleaned with a droplet of a cleaning solution by using a nozzle cleaning device, thereby removing unnecessary substances attached in the vicinity of the opening and stabilizing the discharge state. A second object is to provide a nozzle cleaning method for a liquid dispensing apparatus.
[0007]
[Means for Solving the Problems]
In order to achieve the first object, the first invention described in claim 1 uses a liquid discharge head including a liquid holding member for holding a liquid therein and a nozzle having a liquid discharge opening. In the liquid dispensing apparatus that discharges the liquid held in the liquid holding member from the opening of the nozzle, the nozzle cleaning apparatus performs cleaning of the nozzle, and is provided at a supply position in the vicinity of the nozzle. Cleaning solution supply means for forming and supplying droplets to the nozzle, and cleaning for supplying the cleaning solution droplets supplied to the nozzle from the cleaning solution supply means at the suction position in the vicinity of the nozzle And a solution suction means.
[0008]
In the first invention, when cleaning the nozzle having the liquid discharge opening of the liquid discharge head of the liquid dispensing apparatus, the cleaning solution formed by the cleaning solution supply means provided at the supply position in the vicinity of the nozzle The droplets of the cleaning solution supplied to the nozzle from the cleaning solution supply unit are sucked by the cleaning solution suction unit provided at the suction position near the nozzle.
According to the first aspect of the present invention, the cleaning solution supplying means supplies the cleaning solution droplets to the nozzle having the liquid discharge opening, and the cleaning solution suction means sucks the cleaning solution droplets attached to the nozzle by the cleaning solution suction means. Since the method is employed, the nozzle having the liquid discharge opening becomes wet with the droplets of the cleaning solution during the cleaning. Therefore, as in the above prior art using a dry cleaning method, the substance dissolved in the solution hardly adheres to the vicinity of the liquid discharge opening as a precipitate, and does not need to adhere to the vicinity of the liquid discharge opening. Since this unnecessary liquid is also removed by suction by the cleaning solution suction means, the discharge state is not near the liquid discharge opening of the nozzle. There is no substance to stabilize, and the discharge state can be stabilized.
[0009]
According to a second aspect of the present invention, a liquid recovery tank for recovering the liquid is provided at a recovery position spaced a predetermined distance from the nozzle in the liquid discharge direction.
[0010]
According to the second aspect of the invention, since the liquid recovery tank for recovering the liquid is provided at the recovery position that is separated from the nozzle in the liquid discharge direction by a predetermined distance, When the liquid droplets of the cleaning solution that has absorbed the residual liquid adhering to the opening of the liquid droplets fall from the nozzle without being completely sucked by the cleaning solution suction means, they are collected in the liquid recovery tank. It is possible to prevent the liquid dispensing apparatus from being contaminated.
[0011]
According to a third aspect of the present invention, the cleaning solution supply unit includes a cleaning solution introduction unit that selectively introduces any one of a plurality of types of cleaning solutions.
[0012]
According to the third aspect of the invention, the cleaning solution supply means includes cleaning solution introduction means for selectively introducing any one of a plurality of types of cleaning solutions, so that one type of cleaning solution has a desired cleaning effect. For nozzle contamination that cannot be expected, the nozzle can be cleaned using a plurality of types of cleaning solutions by switching the cleaning solution used, and a desired cleaning effect can be obtained.
[0013]
According to a fourth aspect of the present invention, there is provided a plurality of the cleaning solution supply means and a plurality of the cleaning solution suction means, and a waste liquid means for draining the cleaning solution selectively sucked by any one of the cleaning solution suction means. It is characterized by providing.
[0014]
According to the fourth aspect of the invention, a plurality of the cleaning solution supply means and a plurality of the cleaning solution suction means are provided, and a waste liquid means for selectively draining the cleaning solution sucked by any one of the cleaning solution suction means is provided. Therefore, for the contamination of the nozzle where a desired cleaning effect cannot be expected with one type of cleaning solution, the nozzle is cleaned using a plurality of types of cleaning solution by a plurality of types of cleaning solution supply means and cleaning solution suction means. And a desired cleaning effect can be obtained. Further, a plurality of types of cleaning solutions can be supplied to different parts of the nozzle by using a plurality of cleaning solution supply means, and the cleaning solution sucked by any one of the cleaning solution suction means can be selectively discarded. As a result, the passage of the cleaning solution droplets on the nozzle can be selected, so that the cleaning range of the nozzle is expanded compared with the case where a pair of cleaning solution supply means and cleaning solution suction means are used, and the cleaning effect. Will increase.
[0015]
A fifth aspect of the present invention is characterized in that a plurality of the cleaning solution supply means are provided, and at least one cleaning solution suction means is commonly installed for the plurality of cleaning solution supply means. .
[0016]
According to the fifth invention, a plurality of the cleaning solution supply means are provided, and at least one cleaning solution suction means is commonly installed for the plurality of cleaning solution supply means. For the contamination of the nozzles where the cleaning effect cannot be expected, a plurality of types of cleaning solutions are sequentially or simultaneously supplied from the plurality of cleaning solution supply units and sucked by at least one cleaning solution suction unit provided in common. Accordingly, the nozzle can be cleaned using a plurality of types of cleaning solutions sequentially or simultaneously, and a desired cleaning effect can be obtained. Furthermore, since a plurality of types of cleaning solutions can be supplied sequentially or simultaneously to different parts of the nozzle using a plurality of cleaning solution supply means, compared with the case where a set of cleaning solution supply means and cleaning solution suction means is used. As a result, the cleaning range of the nozzle is greatly expanded, and the cleaning effect is further increased.
[0017]
According to a sixth aspect of the present invention, at least one cleaning solution supply means is disposed above the opening of the nozzle.
[0018]
According to the sixth aspect of the present invention, since at least one of the cleaning solution supply means is disposed above the opening of the nozzle, droplets are attached to the side surface and the opening of the nozzle by the cleaning solution supply means. As a result, not only the opening of the nozzle but also the side surface of the nozzle can be cleaned.
[0019]
In order to achieve the second object, a seventh invention according to claim 7 is a nozzle cleaning device that performs nozzle cleaning using the nozzle cleaning device of the liquid dispensing device according to any one of the first to sixth inventions. A method is characterized in that a cleaning solution droplet is supplied to and attached to the nozzle, and the nozzle is cleaned by sucking the cleaning solution droplet attached to the nozzle.
[0020]
According to the seventh aspect, when the nozzle is cleaned using the nozzle cleaning device of the liquid dispensing device according to any one of the first to sixth aspects, the droplets of the cleaning solution are supplied to and adhered to the nozzle. In addition, since the nozzle is cleaned by sucking the droplets of the cleaning solution adhering to the nozzle, the same effect as the first invention can be obtained.
[0021]
According to an eighth aspect of the present invention, the nozzle is cleaned using a plurality of types of cleaning solutions.
[0022]
According to the eighth invention, the nozzle is cleaned using a plurality of types of cleaning solutions (in the case of the nozzle cleaning device of the third invention, the nozzles are cleaned by switching a plurality of types of cleaning solutions, and the fourth invention In the case of this nozzle cleaning device, the nozzles are cleaned using a plurality of types of cleaning solutions, and in the case of the nozzle cleaning device of the fifth aspect, a plurality of types of cleaning solutions supplied sequentially or simultaneously from a plurality of cleaning solution supply means. The nozzles are used to clean the nozzle), so that the same effects as the third to fifth inventions can be obtained.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing a configuration of a main part of a nozzle cleaning device of a liquid dispensing device according to a first embodiment of the present invention. The nozzle cleaning device of the liquid dispensing device of the present embodiment includes a liquid holding member 10 that holds a liquid therein, discharge pressure generating means 11 that fixes and supports the upper portion of the liquid holding member 10, and a liquid discharge opening. In the liquid dispensing device that discharges the liquid held in the liquid holding member 10 from the nozzle port 12 of the nozzle 13 using the liquid discharge head 14 including the nozzle 13 having the nozzle port 12, the nozzle 13 is cleaned. The cleaning solution supply means 15 is provided at a supply position in the vicinity of the nozzle 13 and forms droplets of the cleaning solution to be supplied to the nozzle 13, and the suction position in the vicinity of the nozzle 13 to supply the cleaning solution. A cleaning solution suction means 16 for sucking droplets of the cleaning solution supplied from the means 15 to the nozzle 13 is provided.
[0024]
The liquid holding member 10 is connected to a liquid supply system (not shown) by a pipe 18. The liquid supply system is configured by sequentially connecting, for example, a syringe piston pump, a solenoid valve, a water pump, and a liquid supply tank from the pipe 18 side. The liquid (discharge solution) is supplied to the liquid holding member 10 by suction by a syringe pump or water supply from a liquid supply tank by a water supply pump.
[0025]
The liquid discharge head 14 is supported by a transport device (not shown), and is arranged so as to be movable between the upper side of the solution recovery tank 17 shown in FIG. 1 and the upper side of a liquid discharge container (not shown). The solution recovery tank 17 is arranged at a recovery position that is separated from the nozzle 10 by a predetermined distance in the liquid discharge direction (in the case of FIG. 1, the direct downward direction). In the nozzle cleaning device of the present embodiment, the outer periphery of the nozzle 13 and the nozzle port 12 are cleaned. Separately, the liquid holding member 10 and the internal flow path of the nozzle 13 are cleaned. Therefore, the solution recovery tank 17 also serves as a cleaning solution recovery tank that recovers the cleaning solution that has flowed through the internal flow paths of the liquid holding member 10 and the nozzle 13.
[0026]
The cleaning solution supply means 15 and the cleaning solution suction means 16 are constituted by stainless thin tubes having an inner diameter φ = 0.05 to 2 mm, for example. The cleaning solution supply means 15 and the cleaning solution suction means 16 are respectively located at the supply position and the suction position in the vicinity of the nozzle port 12 of the nozzle 13 of the liquid ejection head 14 that has moved to the cleaning position provided directly above the solution recovery tank 17. It is installed as shown.
[0027]
The cleaning solution supply unit 15 includes a cleaning solution introduction unit that selectively introduces one of a plurality of types (two types in the illustrated example) of cleaning solutions. The cleaning solution introduction means is one of the water supply pipes 21 and 22 that lead the cleaning solutions 19 and 20 that are fed from two cleaning solution tanks (not shown) by a water pump (not shown) as indicated by the arrows, and the water supply pipes 21 and 22. One is composed of a switching valve (supply path switching means) 24 connected to a water supply pipe 23 connected to the cleaning solution supply means 15. In the present embodiment, two water supply paths to the switching valve 24 are provided, and each water supply path can supply different cleaning solutions to the cleaning solution supply means 15 side as indicated by arrows 19 and 20. That is, when water is supplied from the arrow 19 side, the switching valve 24 is switched to the water supply pipe 21 side, and when water is supplied from the arrow 20 side, the switching valve 24 is switched to the water supply pipe 22 side.
[0028]
The cleaning solution suction means 16 is connected to a suction pump (not shown) via a waste liquid collection tank 25, and by driving the suction pump, droplets of the cleaning solution supplied to the nozzle 13 in the direction indicated by the arrow 26 are generated. The liquid droplets of the cleaning solution are collected as waste liquid in the waste liquid recovery tank 25 by suction.
[0029]
Next, the nozzle cleaning operation by the nozzle cleaning device of the liquid dispensing apparatus of this embodiment will be described with reference to FIG. FIG. 2 is a diagram showing the movement state of the liquid droplets at the tip of the nozzle 13 during cleaning in the first embodiment. The nozzle port 12 formed at the tip of the nozzle 13 has a flow path and liquid in the nozzle 13. It communicates with the pipe 18 via a flow path (both not shown) in the holding member 10. In the present embodiment, the distance between the cleaning solution supply means 15 and the side surface of the tip of the nozzle 13 is such that a droplet (for example, the droplet 27 in FIG. 2) formed by the cleaning solution supply means 15 adheres to the nozzle 13. It is sufficient that the distance is within such a range as possible, for example, 0.1 to 3 mm. Further, the distance between the side surface of the tip of the nozzle 13 and the cleaning solution suction means 16 is a range in which the droplet (for example, the droplet 28 in FIG. 2) attached to the nozzle 13 can be sucked by the cleaning solution suction means 16. For example, the distance is set to 0.1 to 10 mm.
[0030]
When the nozzle 13 is cleaned, the liquid discharge head 14 is moved to the cleaning position above the solution recovery tank 17 by a transport device (not shown) in advance to be in the state shown in FIG.
When the cleaning operation is started in this state, for example, the cleaning solution 19 is selected as the first type of cleaning solution by the switching valve 24, so that the cleaning solution 19 is gradually added by a water supply pump (not shown) connected to the water supply pipe 21. The cleaning solution 19 is introduced into the cleaning solution supply means 15 through the water supply pipe 21, the switching valve 24 and the water supply pipe 23, and is used for cleaning the nozzle 13.
[0031]
Next, the switching solution 24 selects the cleaning solution 20 as the second type of cleaning solution. As a result, the cleaning solution 20 is gradually fed by a water pump (not shown) connected to the water feeding pipe 22, and the cleaning solution 20 is introduced into the cleaning solution supply means 15 through the water feeding pipe 22, the switching valve 24 and the water feeding pipe 23. The nozzle 13 is used for cleaning.
[0032]
During the nozzle cleaning, the movement of the liquid droplets at the tip of the nozzle 13 is as shown in FIG. That is, when the cleaning solutions 19 and 20 are supplied from the cleaning solution supply means 15 to the nozzle 13, the cleaning solution supply means 15 is disposed in the vicinity of the tip of the nozzle 13. As shown in the drawing, the droplets 27 of the cleaning solutions 19 and 20 adhere to the portion near the supply means 15.
[0033]
On the other hand, when a droplet is sucked by the cleaning solution suction means 16 connected to a suction pump (not shown), an air flow is generated as the suction pump is driven. The droplet 27 attached to the nozzle 13 moves in the direction indicated by the arrow 29 in FIG. The droplet 27 that has moved the tip moves as indicated by the droplet 28 in the direction indicated by the arrow 30 in FIG. 2 and is sucked into the cleaning solution suction means 16 together with the airflow. The sucked droplets 28 are recovered by the waste liquid recovery tank 25 shown in FIG. In addition, since the liquid droplets of the cleaning solution dropped from the nozzle 13 without being completely sucked by the cleaning solution suction means 16 are collected in the solution recovery tank 17, the liquid dispensing device is contaminated by the liquid droplets of the cleaning solution that has dropped. Is prevented.
[0034]
According to the nozzle cleaning apparatus of this embodiment, cleaning solution droplets are supplied to the nozzle 13 having the nozzle port 12 by the cleaning solution supply means 15, and the cleaning solution droplets attached to the nozzle 13 are cleaned by the cleaning solution suction means 16. In this case, the nozzle 13 having the nozzle opening 12 is wet with the droplets of the cleaning solution during the cleaning, and is dissolved in the solution as in the conventional technique using the dry cleaning method. The substance hardly adheres to the vicinity of the nozzle opening as a deposit, and the substances that adhere to the vicinity of the nozzle opening are unnecessary liquids (for example, liquids such as samples and reagents remaining after dispensing), and these unnecessary liquids are also washed. Since it is removed by suction by the solution suction means 16, there is no substance that makes the discharge state unstable in the vicinity of the nozzle opening 12 of the nozzle 13, and the discharge state It can be stabilized.
[0035]
In addition, according to the nozzle cleaning device of the present embodiment, the cleaning effect according to the cleaning condition is obtained by setting the cleaning condition at the time of the cleaning operation in which the supply and suction of the droplet of the cleaning solution are repeated as follows. It is done.
[Cleaning condition 1]
The cleaning solution supply means 15 forms several drops of cleaning solution per second and supplies them to the nozzle 13. At the same time as the supply, the cleaning conditions are set so that the cleaning solution suction means 16 sucks the cleaning solution droplets. In this case, the supply and suction of the liquid droplets of the cleaning solution are repeated, and the liquid droplets 27 and 28 of the cleaning solution sequentially pass through the tip of the nozzle 13 in the directions of arrows 29 and 30, respectively. Even if the deposits are present in the vicinity of the outer peripheral portion of the nozzle 13 and the nozzle opening 12, the deposits can be washed away.
[0036]
[Cleaning condition 2]
The cleaning solution supply means 15 continuously forms several drops of cleaning solution at about 1 drop per second and supplies them to the nozzle 13. At the same time as the supply, the cleaning solution suction means 16 sucks the cleaning solution droplets. When the cleaning conditions are set so that the droplet 27 passes through the nozzle port 12 of the liquid discharge head 14, the droplet 27 supplies (supplements) moisture to the surface of the discharge solution filled in the nozzle port 12. become. For this reason, even if the surface of the discharge solution in the nozzle port 12 becomes thicker or hardens due to drying and the discharge state of the discharge solution becomes unstable, the water content By replenishing, the discharge state can be restored to a desired state by gradually decreasing the viscosity of the discharge solution surface or gradually dissolving the solid solution surface.
[0037]
[Cleaning condition 3]
After the droplet 27 is attached in a state in which the droplet 27 supplied from the cleaning solution supply means 15 wraps around the tip of the nozzle 13, deposits (residual liquid etc.) around the outer periphery of the nozzle 13 and the nozzle port 12. ) Is dissolved for a certain period of time until it is dissolved in the droplet 27, and then the cleaning condition is set so that the cleaning solution suction means 16 sucks the cleaning solution droplet, the surface of the discharged solution in the nozzle port 12 is Even in the case of solidification and no discharge, the solidified solution surface can be dissolved over time to restore the discharge state to a desired state.
[0038]
Moreover, according to the nozzle cleaning apparatus of this embodiment, the cleaning solution supply means 15 includes the switching valve 24 that selectively introduces one of a plurality of types (two types in the case of FIG. 1) of cleaning solutions. Therefore, for the contamination of the nozzle where a desired cleaning effect cannot be expected with one type of cleaning solution, a plurality of types of cleaning solutions (two types in FIG. 1) are used by switching the cleaning solution used. Thus, the nozzle can be cleaned, and a desired cleaning effect can be obtained.
[0039]
Below, the suitable combination of two types of washing | cleaning solutions according to contamination is illustrated.
When the desired cleaning effect cannot be expected with only water as the first cleaning solution, a surfactant is used as the second cleaning solution, for example, when the discharge solution to be cleaned contains oils and fats. If the discharge solution to be cleaned contains a body fluid such as blood, a buffer is used. If the discharge solution to be cleaned contains a substance having a polarity such as DNA, an acid or alkali is used. By preparing the above various cleaning solutions so as to use a solution or the like, the nozzle can be reliably cleaned. Alternatively, when a solution containing bacteria such as E. coli is discharged, the tip of the nozzle 12 can be sterilized by preparing a disinfectant solution.
[0040]
Furthermore, since the nozzle cleaning device of the present embodiment is configured to perform cleaning with droplets instead of running water, the amount of waste liquid can be reduced, and this is the case when a biological sample, bacteria, poisons, etc. are discharged. However, it is possible to reduce the generation of waste liquids containing these, which require strict treatment, and reduce the cost and environmental burden.
[0041]
FIG. 3 is a diagram showing the configuration of the main part of the nozzle cleaning device of the liquid dispensing device according to the second embodiment of the present invention. The nozzle cleaning device of the liquid dispensing apparatus of this embodiment is provided with a plurality of cleaning solution supply means and cleaning solution suction means (two sets in the case of this embodiment) as compared with the first embodiment. A modification is provided in which a waste liquid means for draining the cleaning solution selectively sucked by the two cleaning solution suction means is provided.
[0042]
That is, as shown in FIG. 3, the nozzle cleaning apparatus of the present embodiment is provided at the first supply position in the vicinity of the nozzle 13 of the liquid ejection head 14, and forms a droplet of the first cleaning solution 31 to show the arrow. As shown by 32, the cleaning solution supply means 33 supplied to the nozzle 13 and the liquid of the first cleaning solution 31 provided at the first suction position in the vicinity of the nozzle 13 and supplied from the cleaning solution supply means 33 to the nozzle 13 A cleaning solution suction means 34 for sucking the droplets and a cleaning solution provided at a second supply position in the vicinity of the nozzle 13 to form a droplet of the second cleaning solution 35 and supply it to the nozzle 13 as indicated by an arrow 36 A supply means 37; a cleaning solution suction means 38 that is provided at a second suction position in the vicinity of the nozzle 13 and sucks a droplet of the second cleaning solution 35 supplied to the nozzle 13 from the cleaning solution supply means 37; Solution suction means By any one of 7, 38 consisting comprises a selectively switching valve (suction path switching means) for switching the flow path for the sucked cleaning solution to waste into the waste collection tank 25 39 or the like. In FIG. 3, the cleaning solution supply means 33 and 37 and the cleaning solution suction means 34 and 38 are shown obliquely with respect to the liquid ejection head 14, but actually, the cleaning solution supply means 33 and 37 and the cleaning solution are shown. As in the first embodiment, the suction units 34 and 38 are provided with a first supply position, a second supply position, a first suction position, and a first suction position set on the same horizontal plane in the vicinity of the tip of the nozzle 13 of the liquid ejection head 14. The two cleaning solution supply means and the cleaning solution suction means are arranged so as to be orthogonal to each other.
[0043]
The cleaning solution supply means 33 and 37 are respectively connected to cleaning solution tanks containing different types of cleaning solutions via different cleaning solution feed pumps (not shown). When supplying droplets of the first cleaning solution 31 from the cleaning solution supply means 33, the cleaning solution 31 is supplied in the direction indicated by the arrow 31 by driving the cleaning solution water supply pump connected to the cleaning solution supply means 33. When the droplets of the cleaning solution 35 are supplied from the cleaning solution supply unit 37, the cleaning solution 35 is supplied in the direction indicated by the arrow 35 by driving the cleaning solution water supply pump connected to the cleaning solution supply unit 37. It has come to be.
[0044]
Next, the nozzle cleaning operation by the nozzle cleaning device of the liquid dispensing device of this embodiment will be described with reference to FIG. When the nozzle 13 is cleaned, the liquid ejection head 14 is moved in advance to the cleaning position above the solution recovery tank 17 by a transport device (not shown) to be in the state shown in FIG.
When the first cleaning solution 31 is selected for cleaning, the cleaning solution 31 is gradually sent out by driving a cleaning solution water supply pump (not shown) and introduced into the cleaning solution supply means 33. On the other hand, when the second cleaning solution 35 is selected for cleaning, the cleaning solution 35 is gradually sent out by driving a cleaning solution water pump (not shown) and introduced into the cleaning solution supply means 37.
[0045]
During the nozzle cleaning, the movement of the liquid droplets at the tip of the nozzle 13 is as shown in FIG. FIG. 4 is a view showing a state of movement of the droplets at the tip of the nozzle 13 during cleaning in the second embodiment, and shows a state in which the nozzle 13 is looked up from directly below. Since the cleaning solution supply means 33 and 37 and the cleaning solution suction means 34 and 38 are arranged in the vicinity of the tip of the nozzle 13 of the liquid discharge head 14, the path for guiding the first cleaning solution 31 is selected. The guided first cleaning solution 31 forms a droplet 40 at the tip of the cleaning solution supply means 33, and the formed droplet 40 adheres to the nozzle 13 as shown. Similarly, the second cleaning solution 35 guided when the path for guiding the second cleaning solution 35 is selected forms a droplet 41 at the tip of the cleaning solution supply means 37, and the formed droplet 41 Adheres to the nozzle 13 as shown.
[0046]
On the other hand, when the droplets are sucked by the cleaning solution suction means 34 and 38 connected to a suction pump (not shown), an air flow is generated as the suction pump is driven as in the first embodiment. Thereby, the droplets 40 and 41 adhering to the nozzle 13 move in the directions indicated by the arrows 32 and 36 in FIG. 4 on the tip surface 42 where the nozzle opening 12 of the nozzle 13 is formed by the air flow. The droplets 40 and 41 that have moved on the tip surface 42 are sucked into the cleaning solution suction means 34 and 38 together with the airflow. The sucked liquid droplets are collected by the waste liquid collection tank 25 shown in FIG. In addition, since the liquid droplets of the cleaning solution dropped from the nozzle 13 without being completely sucked by the cleaning solution suction means 34 and 38 are collected in the solution recovery tank 17, the liquid dispensing device is contaminated by the liquid droplets of the cleaning solution that has dropped. Is prevented.
[0047]
According to the nozzle cleaning apparatus of this embodiment, the cleaning solution droplets 40 and 41 are selectively supplied to the nozzle 13 having the nozzle port 12 by the cleaning solution supply means 33 and 37, and the cleaning solution adhering to the nozzle 13 is supplied. Since the wet cleaning method in which the droplets 40 and 41 are selectively sucked by the cleaning solution suction means 34 and 38 is adopted, the nozzle 13 having the nozzle port 12 becomes wet with the droplets of the cleaning solution during the cleaning, and is dry. The substance dissolved in the solution as in the above prior art using the cleaning method hardly adheres to the vicinity of the nozzle mouth as a precipitate, and the matter adhering to the vicinity of the nozzle mouth remains unnecessary liquid (for example, remains after dispensing). Since the unnecessary liquid is also removed by selective suction by the cleaning solution suction means 34 and 38, the liquid near the nozzle opening 12 of the nozzle 13 is removed. The material to destabilize the discharge state is completely ceases to exist, the ejection state can be stabilized on.
[0048]
Further, according to the nozzle cleaning device of the present embodiment, the cleaning conditions during the cleaning operation in which the supply and suction of the droplets of the cleaning solution are repeated are set in the same manner as in the first embodiment, for example. Similarly, a cleaning effect corresponding to the cleaning conditions can be obtained.
Furthermore, according to the nozzle cleaning apparatus of the present embodiment, since the two cleaning solutions supply means are used to supply two types of cleaning solutions to different portions of the nozzle 13 to clean the nozzles, one set of cleaning solutions Compared with the case where the supply means and the cleaning solution suction means are used, the cleaning range of the nozzle is expanded, and the suction path is switched so that the cleaning solution passes through the portion where the tip surface 42 of the nozzle 13 is desired to be cleaned. By switching the means 39, it becomes possible to select the path of the cleaning solution, and the deposits around the nozzle opening 12 can be surely washed away, so that the cleaning effect is increased.
[0049]
In the second embodiment, two sets of the cleaning solution supply means and the cleaning solution suction means are used. However, the cleaning solution supply means and the cleaning solution suction means do not have to be paired, and a plurality of cleaning solution supply means and at least One cleaning solution suction means may be used, or at least one cleaning solution supply means and a plurality of cleaning solution suction means may be used.
[0050]
FIG. 5 is a diagram showing a configuration of a main part of a nozzle cleaning device of a liquid dispensing device according to a third embodiment of the present invention. The nozzle cleaning device of the liquid dispensing device of the present embodiment is provided with a plurality (in this case, four) of cleaning solution supply means with respect to the first embodiment, and at least one cleaning solution supply means is provided. In this case, one (1) cleaning solution suction means is installed in common, and at least one cleaning solution supply means is changed above the nozzle port 12 of the nozzle 13.
[0051]
That is, in the nozzle cleaning apparatus of the present embodiment, as shown in FIG. 5, cleaning solution supply means 51 to 54 are provided at the first suction position to the fourth suction position in the vicinity of the nozzle 13 of the liquid ejection head 14, respectively. The cleaning solution suction means 55 is provided at the common suction position in the vicinity of the nozzle 13. In the illustrated example, all of the cleaning solution supply units 51 to 54 are arranged above the nozzle port 12, and the cleaning solution suction unit 55 is arranged so that the suction side end thereof is arranged below the nozzle port 12. It has become. The cleaning solution supply means 51 to 54 are connected to a cleaning solution tank containing a cleaning solution via a cleaning solution feed pump (not shown), and the cleaning solution suction means 55 is a waste liquid (not shown) as in the first embodiment. It is connected to a suction pump (not shown) through a recovery tank. The cleaning solution supply means 51 to 54 include a plurality of cleaning solution tanks containing different cleaning solutions (in this case, a maximum of four types of cleaning solutions and at least two types of cleaning solutions) via different cleaning solution feed pumps (not shown). It may be connected to.
[0052]
In the above, the position at which the suction side end of the cleaning solution suction means 55 is provided is preferably directly below the nozzle port 12 in order to uniformly suction each cleaning solution supply unit, but is provided directly below the nozzle port 12. In such a case, the cleaning solution for cleaning the internal flow paths of the liquid holding member 10 and the nozzle 13 may be hindered to drop, and therefore, the liquid holding member 10 and the nozzle 13 are provided at positions slightly shifted from directly below. Further, the installation angle of the cleaning solution suction means 55 is an angle close to horizontal in the illustrated example, but may be an angle close to vertical. Further, it is preferable to make the diameter of the cleaning solution suction means 55 larger than the diameter of the cleaning solution supply means 51 to 54 in order to suck the droplets of the cleaning solution supplied from the four cleaning solution supply means 51 to 54. .
[0053]
Next, the nozzle cleaning operation by the nozzle cleaning device of the liquid dispensing device of this embodiment will be described with reference to FIG. When the nozzle 13 is cleaned, the liquid discharge head 14 is moved in advance to a cleaning position above a solution recovery tank (not shown) by a transfer device (not shown) to be in the state shown in FIG.
By driving a cleaning solution feed pump (not shown), the cleaning solution is gradually sent out and introduced into the cleaning solution supply means 51 to 54. Since the cleaning solution supply means 51 to 54 and the cleaning solution suction means 55 are disposed in the vicinity of the tip of the nozzle 13 of the liquid discharge head 14, the introduced cleaning solution is the cleaning solution supply means as shown in FIG. The cleaning solution droplets 56 to 59 adhere to the tips of 51 to 54.
[0054]
Here, an air flow accompanying suction is generated by the cleaning solution suction means 55 by driving a suction pump (not shown). The droplets 56 to 59 adhering to the nozzle 13 move as indicated by the arrow 60 on the side surface and the tip portion of the nozzle 13 due to the downward movement due to the airflow and the weight of the droplet. It is sucked into the suction means 59. The sucked liquid droplets are collected by the waste liquid collection tank as in the first embodiment. The droplets of the cleaning solution that have fallen from the nozzle 13 without being completely sucked by the cleaning solution suction means 59 are also collected in the solution recovery tank as in the first embodiment. Contamination of the liquid dispensing device is prevented.
[0055]
According to the nozzle cleaning apparatus of the present embodiment, the cleaning solution droplets 56 to 59 are supplied to the nozzle 13 having the nozzle port 12 by the cleaning solution supply means 51 to 54, and the cleaning solution droplet 56 attached to the nozzle 13. Since the wet cleaning method in which ~ 59 is sucked in common by the cleaning solution suction means 55 is adopted, the nozzle 13 having the nozzle port 12 becomes wet with the droplets of the cleaning solution during the cleaning, and the conventional method using the dry cleaning method is used. Substances dissolved in the solution are hardly deposited as deposits in the vicinity of the nozzle opening as in the case of technology, and those that adhere near the nozzle opening are unnecessary liquids (for example, liquids such as samples and reagents remaining after dispensing) Since this unnecessary liquid is also removed by suction by the cleaning solution suction means 55, the discharge state becomes unstable in the vicinity of the nozzle port 12 of the nozzle 13. It can be totally cease to exist, to stabilize the ejection state.
[0056]
Further, according to the nozzle cleaning device of the present embodiment, the cleaning conditions during the cleaning operation in which the supply and suction of the droplets of the cleaning solution are repeated are set in the same manner as in the first embodiment, for example. Similarly, a cleaning effect corresponding to the cleaning conditions can be obtained.
Furthermore, according to the nozzle cleaning apparatus of the present embodiment, a plurality of types of cleaning solutions are supplied to different parts of the nozzle 13 sequentially or simultaneously using four cleaning solution supply means and one common cleaning solution suction means 55. Therefore, the cleaning range of the nozzle is greatly expanded as compared with the case of using a single set of clean solution supply means and cleaning solution suction means, and cleaning of the side portion and the tip portion of the nozzle 13 can be performed. Since it becomes possible to select the path of the cleaning solution so that the cleaning solution passes through the desired site, the deposits around the side surface of the nozzle 13 and the nozzle port 12 can be surely washed away. The cleaning effect is further increased.
[0057]
In the third embodiment, a plurality (four) of cleaning solution supply means and one cleaning solution suction means are used. However, at least one cleaning solution supply means and a plurality of cleaning solution suction means are used. Also good. As in the first embodiment, the cleaning solution supply unit may be provided with a cleaning solution introduction unit that selectively introduces any one of a plurality of types of cleaning solutions. Further, in the present embodiment, when a plurality of cleaning solution suction means are provided, an electromagnetic valve (stage suction path switching means) may be provided in the cleaning solution suction means as in the second embodiment. Good.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a configuration of a main part of a nozzle cleaning device of a liquid dispensing device according to a first embodiment of the present invention.
FIG. 2 is a view for explaining a nozzle cleaning operation by a nozzle cleaning device of the liquid dispensing apparatus of the first embodiment.
FIG. 3 is a diagram illustrating a configuration of a main part of a nozzle cleaning device of a liquid dispensing device according to a second embodiment of the present invention.
FIG. 4 is a diagram for explaining a nozzle cleaning operation by a nozzle cleaning device of a liquid dispensing apparatus according to a second embodiment.
FIG. 5 is a diagram for explaining a configuration of a main part of a nozzle cleaning device and a nozzle cleaning operation of a liquid dispensing device according to a third embodiment of the present invention.
FIG. 6 is a diagram for explaining a conventional technique.
[Explanation of symbols]
10 Liquid holding member
11 Discharge pressure generating means
12 Nozzle port (opening for liquid discharge)
13 nozzles
14 Liquid discharge head
15 Cleaning solution supply means
16 Cleaning solution suction means
17 Solution recovery tank
18 Piping
19, 20 Cleaning solution (arrow indicating the flow of cleaning solution)
21, 22, 23 Piping
24 selector valve (supply path switching means)
25 Waste liquid recovery tank
26 Waste liquid (arrow indicating the flow of waste liquid)

Claims

Liquid dispensing for discharging the liquid held in the liquid holding member from the opening of the nozzle using a liquid discharge head comprising a liquid holding member for holding liquid inside and a nozzle having a liquid discharge opening. In the apparatus, a nozzle cleaning device for cleaning the nozzle,
A cleaning solution supply means provided at a supply position in the vicinity of the nozzle and forming a droplet of the cleaning solution and supplying the droplet to the nozzle;
A liquid dispensing apparatus comprising: a cleaning solution suction unit that is provided at a suction position near the nozzle and sucks a droplet of the cleaning solution supplied from the cleaning solution supply unit to the nozzle. Nozzle cleaning device.

2. The nozzle cleaning device for a liquid dispensing apparatus according to claim 1, wherein a liquid recovery tank for recovering the liquid is provided at a recovery position spaced apart from the nozzle by a predetermined distance in the liquid discharge direction.

3. The nozzle cleaning device for a liquid dispensing apparatus according to claim 1, wherein the cleaning solution supply unit includes a cleaning solution introduction unit that selectively introduces one of a plurality of types of cleaning solutions.

A plurality of the cleaning solution supply means and a plurality of the cleaning solution suction means are provided, respectively, and a waste liquid means for draining the cleaning solution selectively sucked by any one of the cleaning solution suction means is provided. 3. A nozzle cleaning device for a liquid dispensing device according to 1 or 2.

3. A liquid dispensing apparatus according to claim 1, wherein a plurality of said cleaning solution supply means are provided, and at least one cleaning solution suction means is commonly installed for said plurality of cleaning solution supply means. Nozzle cleaning device.

6. The nozzle cleaning device for a liquid dispensing apparatus according to claim 5, wherein at least one cleaning solution supply means is disposed above the opening of the nozzle.

A nozzle cleaning method for cleaning a nozzle using the nozzle cleaning device of the liquid dispensing device according to any one of claims 1 to 6,
Nozzle cleaning of a liquid dispensing apparatus, wherein the nozzle is cleaned by supplying a droplet of the cleaning solution to the nozzle and adhering the droplet, and sucking the droplet of the cleaning solution adhering to the nozzle Method.

The nozzle cleaning method for a liquid dispensing apparatus according to claim 7, wherein the nozzle is cleaned using a plurality of types of cleaning solutions.