JP2004284027A

JP2004284027A - Liquid droplet ejection recorder, and ink filling method and function preserving method

Info

Publication number: JP2004284027A
Application number: JP2003075345A
Authority: JP
Inventors: Katsuhisa Sakuma; 勝久佐久間; Akitomo Koujiyama; 明智柑子山; Hideyuki Nagata; 英行永田
Original assignee: SII Printek Inc
Current assignee: SII Printek Inc
Priority date: 2003-03-19
Filing date: 2003-03-19
Publication date: 2004-10-14
Anticipated expiration: 2023-03-19
Also published as: JP4256184B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide the arrangement and ink filling or preserving method of a liquid droplet ejection recorder which can be provided with a pressure damper even when a function preserving operation for filling a liquid droplet ejection recording head with ink or entirely ejecting ink therefrom is performed by means of a pressure pump, and to provide an arrangement of the liquid droplet ejection recorder where ink supply by means of the pressure pump is not always required during ordinary print operation. <P>SOLUTION: The liquid droplet ejection recorder comprises an ink container, an ink supply passage provided with a pressure damper communicating with the ink container, an ink supply bypath joining the ink supply passage between the pressure damper and the liquid droplet ejection recording head while branching from the ink supply passage at a position closer to the ink container than the pressure damper and provided with at least one pressure pump, and a valve mechanism for switching interconnection of the ink supply bypath and the ink supply passage appropriately. The valve mechanism is switched after the pressure damper is filled with ink through the sucking function of the pressure pump, and the liquid droplet ejection recording head is filled with ink through the pressurizing function of the pressure pump or ink is ejected entirely therefrom. Ink is supplied from the ink container through the ink supply passage during ordinary print operation. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、例えば、プリンタ、ファックスなどに適用され、記録媒体に液滴を噴射し、該記録媒体に印字する液滴噴射式記録装置、およびインク充填方法と機能保全方法に関する。
【０００２】
【従来技術】
従来から、インクを吐出する複数のノズルを有する液滴噴射式記録ヘッドを用いて被記録媒体に文字や画像を記録する液滴噴射式記録装置が知られている。かかる液滴噴射式記録装置では、被記録媒体へ文字や画像の記録を開始する前に、前記液滴噴射式記録ヘッドにインクを充填したり、印字品質を維持するために必要に応じて該液滴噴射式記録ヘッドを初期状態に戻す等の機能保全をする必要がある。
【０００３】
このような液滴噴射式記録ヘッドのインク充填や機能保全に使用される液滴噴射式記録装置２００の一例の概略図を図７に示す。
【０００４】
図７に示すように、従来技術において前記液滴噴射式記録装置２００は、インク容器１００と、該インク容器１００からインクを導出する加圧ポンプ１０１と、該加圧ポンプ１０１によって送り込まれた前記インクの圧力がその内部で一定以上になるまで保持する蓄圧部１０２と、前記加圧ポンプ１０１と前記蓄圧部１０２の間に設置され、前記インクを前記インク容器１００から前記蓄圧部１０２へ供給するインク供給路１０３を適宜開閉する弁機構１０４と、ノズル１０５を具備する液滴噴射式記録ヘッド１０６と、前記蓄圧部１０２と前記液滴噴射式記録ヘッド１０６の間に設置されたインク供給路１０３を適宜開閉する弁機構１０７と、前記ノズル１０５が開口するノズル開口面１０８を拭う図示しない拭き取り装置と、前記ノズル１０５の全てを平面的に覆う図示しない受け部を少なくとも具備している。
【０００５】
前記液滴噴射式記録ヘッド１０６へのインク充填方法は、まず弁機構１０７を閉、弁機構１０４を開とした状態で加圧ポンプ１０１を作動させ、蓄圧部１０２にインクを送り込んで該蓄圧部１０２内部の圧力を高めていく。そして蓄圧部１０２内部の圧力が十分に高くなると同時に弁機構１０７を開、弁機構１０４を閉として前記蓄圧部１０２内に貯留したインクを、前記圧力を利用して液滴噴射式記録ヘッド１０６に衝撃的に押し出して充填する。その際ノズル１０５からはインクが溢れ、かつノズル開口面１０８をインクが濡らすので、溢れたインクは前記受け部で受け止め、ノズル開口面１０８を濡らしたインクは前記拭き取り装置で拭き取る（例えば、特許文献１参照。）。
【０００６】
また上記衝撃的な液滴噴射式記録ヘッド１０６に対するインク充填方法を、全てのノズル１０５からインクを吐出させるような前記メンテナンス時において適用することも可能である（例えば、特許文献２参照。）。
【０００７】
【特許文献１】
特開平１１−９１１２８号公報（第２−４頁、第１図）
【０００８】
【特許文献２】
特開平１１−２０７９８５号公報（第２−３頁、第１図）
【０００９】
【発明が解決しようとする課題】
このような液滴噴射式記録装置およびインク充填方法と機能保全方法では、特に前記液滴噴射式記録装置が、液滴噴射式記録ヘッドの近傍のインク供給路上に圧力緩衝器を具備する場合において、従来技術のように前記液滴噴射式記録ヘッドへ蓄圧部に蓄えた高圧を用いた、衝撃的な前記インク充填方法と前記機能保全方法のみならず、前記蓄圧部を使用しないで加圧ポンプのみを用いた、前記インク充填方法と前記機能保全方法を採用する際にも、前記圧力緩衝器が前記インク充填方法と前記機能保全方法に要する加圧圧力に耐え切れず、破壊してしまうので該圧力緩衝器を使用できないという問題が発生していた。
【００１０】
ここで前記圧力緩衝器は、前記液滴噴射式記録ヘッドが走査して印字する場合には該移動によるインクの慣性力による圧力変動を緩和する目的で、前記液滴噴射式記録ヘッドが固定されて印字する場合には該ヘッドに与えられる衝撃等による圧力変動を緩和する目的で使用され、印字品質を良好に保つには必要不可欠な要素である。
【００１１】
また従来技術では、インク供給路に加圧コロが常時接触して該インク供給路をしごくことにより圧力を発生させるチュ−ブポンプ等で加圧ポンプがある場合、該加圧ポンプを停止させると前記加圧コロが前記インク供給路を閉じてしまうため、インク充填後も加圧ポンプを用いてインクを前記液滴噴射式記録ヘッドに供給しつづける必要があり、該供給に要するエネルギ−が無駄であるし、さらに前記加圧ポンプによってインクを供給する場合には、該供給の圧力は脈動となって、前記圧力緩衝器を具備できない液滴噴射式記録ヘッドによる印字品質を、該脈動が著しく損ねるという問題も発生していた。
【００１２】
本発明はこのような事情に鑑み、加圧ポンプによって液滴噴射式記録ヘッドへインクを充填、全吐出等する機能保全動作を行う場合でも、圧力緩衝器を具備できる液滴噴射式記録装置の構成とそのインク充填または保全方法を提案し、かつ通常印字時に前記加圧ポンプによるインク供給を常時行わなくてもよい前記液滴噴射式記録装置の構成を提案することを課題とする。
【００１３】
【課題を解決するための手段】
上記課題を解決する本発明の態様は、インクを内部に貯留するインク容器と、該インク容器に連通して、液滴噴射式記録ヘッドに供給する前記インクの供給圧力の変動を緩和する、圧力緩衝器を具備するインク供給路と、該圧力緩衝器よりも前記インク容器に近い位置で前記インク供給路から分岐し、前記圧力緩衝器と液滴噴射式記録ヘッドの間で前記インク供給路に合流して、少なくとも１個の圧力ポンプを具備するインク供給迂回路と、該インク供給迂回路と前記インク供給路の連通状態を適宜切り替え可能な弁機構を少なくとも備えており、前記圧力ポンプのインクを満たす対象を負圧にして該インクを導く吸引機能によって前記圧力緩衝器にインクを満たした後で前記弁機構を切り替え、前記圧力ポンプのインクを満たす対象を加圧して該インクを導く加圧機能によって前記液滴噴射式記録ヘッドにインクを充填、または全吐出させ、通常の印字時にはインク容器から前記インク供給路を通してインクは供給されることを特徴とする液滴噴射式記録装置、およびインク充填と機能保全方法にある。
【００１４】
かかる本発明における液滴噴射式記録装置では、前記吸引機能により圧力緩衝器をインクで満たすので該圧力緩衝器の破壊は発生せず、前記加圧機能により液滴噴射式記録ヘッドにインクを充填、または全吐出させるので気泡が該ヘッド内に残留しにくい。さらに前記吸引機能と加圧機能に使用する圧力ポンプを共通化すれば、該圧力ポンプは１台にまとめることができ、使用する圧力ポンプ数を削減可能となる。したがって前記液滴噴射式記録装置製造を低コストで実現しつつ、いかなるタイプの液滴噴射式記録装置においても常に印字品質を保持することを可能にする。
【００１５】
【発明の実施の形態】
以下、本発明の実施の形態に基づいて本発明を詳細に説明する。
【００１６】
図１は、液滴噴射式記録装置５０を示す模式図であり、本発明の実施形態を示す。該液滴噴射式記録装置５０の構成について説明する。
【００１７】
インクを内部に貯留するインク容器１と、該インク容器１から液滴噴射式記録ヘッド８に供給する前記インクの供給圧力の変動を緩和する、圧力緩衝器５を介して液滴噴射式記録ヘッド８にインクを供給するインク供給路２と、圧力緩衝器５の設置位置よりもインク容器１に近い位置に設置された三方弁たる弁機構３と、圧力緩衝器５と液滴噴射式記録ヘッド８の間に設置された三方弁たる弁機構６と、該弁機構６と弁機構３を連通するインク供給迂回路４と、該インク供給迂回路４上に設置された圧力ポンプ７と、インク供給迂回路４上の圧力ポンプ７と弁機構３の間に設置された三方弁たる弁機構１１と、該弁機構１１にてインク供給迂回路４から分岐し、インクを排出するためのインク排出管１２と、液滴噴射式記録ヘッド８が具備するノズル９が表面に開口するノズル開口面１０と、該ノズル開口面１０と鉛直方向に対向しかつ全てのノズル９が分布する平面領域を覆う受け部１３と、該受け部１３の底面で連通する廃液路１４と、インク排出管１２と廃液路１４から排出されたインクを貯留する廃インク容器１５と、で該液滴噴射式記録装置５０は少なくとも構成されている。
【００１８】
図１におけるＡはインク容器１に貯留されたインク液面とノズル開口面１０の鉛直方向距離を示し、これはノズル９にメニスカスを形成するために必要な圧力水頭を発生させるための水頭差である。また圧力緩衝部５は液滴噴射式記録ヘッド８に供給されるインクの圧力変動を抑制する目的で設置しているので、可能な限り液滴噴射式記録ヘッド８の近傍に設置することが望ましい。特に液滴噴射式記録ヘッド８を走査して印字する液滴噴射式記録装置５０の場合は、図１のＢで示す領域の圧力緩衝器５、弁機構６、および液滴噴射式記録ヘッド８をキャリッジに搭載する必要がある。
【００１９】
図１の場合、弁機構３、弁機構６、弁機構１１は全て三方弁であるが、弁機構３と弁機構６はインク供給路２とインク供給迂回路４の連通状態を適宜選択可能な要素であれば何でもよく、例えば、電磁弁等の複数個の開閉弁を組合せた構成であっても問題はない。弁機構１１も同様にインク供給迂回路４とインク排出管１２の連通状態を適宜選択可能な要素であれば何でもよい。
【００２０】
なお、図１における圧力ポンプ７はインクを満たす対象を負圧にして該インクを導く吸引機能と、インクを満たす対象を加圧して該インクを導く加圧機能の両方を具備する、例えばチュ−ブを加圧コロでしごくことで圧力を発生させるチュ−ブ式ポンプであり、１個のみ使用しているが、図６のように吸引機能のみを有する吸引ポンプ１６と、加圧機能のみを有する加圧ポンプ１７を並列配置して圧力ポンプを複数使用してもよく、ここで使用可能な吸引ポンプ、加圧ポンプの例として、前記チュ−ブ式ポンプやインクを圧送するためのダイヤフラム式ポンプ、インクを圧送するためのピストン−シリンダ式のポンプが挙げられる。
【００２１】
本発明では、液滴噴射式記録ヘッド８へ加圧によってインク充填されるので、受け部１３をノズル開口面１０に密着させてノズル９を密閉する必要はなく、全てのノズル９から漏出するインクを漏れなく受け止めることができる位置に受け部１３を配置するのみで十分である。よって受け部１３を上下動させる駆動装置は必要ない。また、受け部１３を介してインクを吸引して液滴噴射式記録ヘッド８にインクを充填することはないので、廃液路１４は吸引ポンプを具備する必要はなく、受け部１３によるノズル開口面１０との密閉空間を大気圧と平衡状態とするための大気開放弁も必要ない。
【００２２】
また本発明では、圧力緩衝器５の内部に吸引によってインクを満たすので、圧力緩衝器５が空気層を有するタイプのものであってもインクを満たしている間に圧力緩衝器５が破壊することはない。
【００２３】
次に図１で示した液滴噴射式記録装置５０における、液滴噴射式記録ヘッド８に対するインク充填方法と機能保全方法について、図２から図５を用いて説明する。
【００２４】
図２は液滴噴射式記録ヘッド８にインクを充填する前に必要な、圧力緩衝器５およびインク供給路２にインクを満たす過程を示す。
【００２５】
図２では、弁機構３にてインク供給路２とインク供給迂回路４を連通させず、インク容器１と圧力緩衝器５を連通させ、弁機構６にて圧力緩衝器５と液滴噴射式記録ヘッド８を連通させず、圧力緩衝器５とインク供給迂回路４を連通させ、弁機構１１にて圧力ポンプ７とインク排出管１２を連通させている。この状態で圧力ポンプ７の吸引機能を作動させ、図２に記す矢印Ｃの方向にインクがインク容器１から流れ、該インクがインク排出管１２を経て廃インク容器１５に適当な時間排出されると、圧力緩衝器５およびインク供給路２にインクは万遍なく満たされる。
【００２６】
この際、インク排出管１２は吸引したインクをインク供給迂回路４から排出するために不可欠な要素である。またインク排出管１２から排出したインクは液滴噴射式記録ヘッド８を経ていないので微細なゴミ等を含んでいる可能性が低く、廃インク容器１５に捨てるのではなく、インク容器１にインク排出管１２を用いて戻してもよい。
【００２７】
図３は、図２に記した過程を終了後、液滴噴射式記録ヘッド８にインクを充填する過程を示す。
【００２８】
図３では、弁機構３にてインク容器１と圧力緩衝器５を連通させず、インク供給路２とインク供給迂回路４を連通させ、弁機構６にて圧力緩衝器５とインク供給迂回路４を連通させず、インク供給迂回路４と液滴噴射式記録ヘッド８を連通させ、弁機構１１にて圧力ポンプ７とインク排出管１２を連通させず、圧力ポンプ７と弁機構３を連通している。この状態で圧力ポンプ７の加圧機能を作動させ、図３に記す矢印Ｄの方向にインクがインク容器１から流れ、該インクがインク供給迂回路４を経て液滴噴射式記録ヘッドに充填される。該充填の過程でノズル９から漏出したインクは受け部１３で全て受け止められ、廃液路１４を介して廃インク容器１５に回収される。
【００２９】
ここで最も重要なことは、図２に示す圧力緩衝器５へインクを満たす過程が終了した後、最初に弁機構３にてインク容器１とインク供給迂回路４を連通させ、圧力緩衝器５とインク容器１の連通を遮断することである。その理由は、弁機構３にて圧力緩衝器５とインク容器１の連通を遮断する前に、弁機構６にて圧力緩衝器５と液滴噴射式記録ヘッド８を一瞬でも連通させ、圧力緩衝器５を大気開放してしまうと、インク供給路２と圧力緩衝器５に満たされていたインクは重力の作用によって抜けてしまうからである。圧力緩衝器５が大気開放される前に弁機構３にて圧力緩衝器５とインク容器１の連通を遮断してしまえば、インク供給路２の一端は密閉されていることとなり、インク供給路２と圧力緩衝器５に満たされていたインクは重力の作用によって抜けてしまうことはない。
【００３０】
図４は図３に記した過程を終了後、液滴噴射式記録ヘッド８が通常印字する状態でのインクを液滴噴射式記録ヘッド８に供給する過程を示す。
【００３１】
図４では、弁機構３にてインク供給路２とインク供給迂回路４を連通させず、インク容器１と圧力緩衝器５を連通させ、弁機構６にてインク供給迂回路４と液滴噴射式記録ヘッド８を連通させず、圧力緩衝器５と液滴噴射式記録ヘッド８を連通させる。この際、弁機構１１の状態は任意の連通状態でよい。この状態でインク容器１から液滴噴射式記録ヘッド８に至る経路にはインクが満たされているので、液滴噴射式記録ヘッド８が印字をすれば印字で消費したインクが自然とインク容器１から矢印Ｅの方向に供給されるのは、従来からよく知られている一般的な液滴噴射式記録装置の場合と同じである。
【００３２】
弁機構３と弁機構６を操作して圧力緩衝器５とインク容器１、または圧力緩衝器５と液滴噴射式記録ヘッド８の連通を確保する順序であるが、これはどちらが先でもよく、当然同時に操作して該連通を確保してもよい。
【００３３】
弁機構３にて圧力緩衝器５とインク容器１を先に連通させた場合は、弁機構６にてインク供給路は密閉されているので、圧力緩衝器５を含むインク供給路２からインクがインク容器１に逆流することはなく、その後、弁機構６にて圧力緩衝器５と液滴噴射式記録ヘッド８を連通させても、図１における水頭差Ａの作用でノズル９にメニスカスが形成されるので問題はないからである。
【００３４】
また弁機構６にて圧力緩衝器５と液滴噴射式記録ヘッド８を先に連通させた場合は、弁機構３にてインク供給路は密閉されているので、圧力緩衝器５を含むインク供給路２からインクがノズル９から重力の作用で抜けることはなく、その後弁機構３にて圧力緩衝器５とインク容器１を連通させても、図１における水頭差Ａの作用でノズル９にメニスカスが形成されるので問題はないからである。
【００３５】
図３におけるインク充填が終了した後、図示しない拭き取り部材でノズル開口面に残留するインクを払拭し、図４のように各要素を連通させれば印字は可能となる。
【００３６】
なお、液滴噴射式記録ヘッド８の通常印字途中で全てのノズル９からインクを吐出させて印字品質を保つ際には、図３に記したのと同じ状態に各要素を連通させ、圧力ポンプ７の加圧機能によってインクを押し出せばよく、ここでも弁機構３と弁機構６の操作順序は制限されない。
【００３７】
図５に液滴噴射式記録ヘッド８を交換する際の各要素の連通状態を示す。弁機構６にて圧力ポンプ７と液滴噴射式記録ヘッド８を連通させ、弁機構１１にてインク排出管１２と圧力ポンプ７を連通させる。その後、圧力ポンプ７の吸引機能、加圧機能のどちらかを用いれば、図５に示す両方向矢印の方向にインクはそれぞれ流れ、インク排出管１２またはノズル９からインクは排出される。ここで圧力ポンプの加圧機能を用いてインクを押し出すと、ノズル開口面１０の表面にインクが残留し、図示しない拭き取り装置で該インクを払拭する必要が生じるので、圧力ポンプの吸引機能を用いてインクをインク排出管１２から排出することが望ましい。
【００３８】
【発明の効果】
以上説明したように本発明では、インク供給迂回路が具備する圧力ポンプの吸引機能により、まずインク供給路が具備する圧力緩衝器にインクを満たした後で、前記圧力ポンプの加圧機能により液滴噴射式記録ヘッドにインクを充填し、さらに該液滴噴射式記録ヘッドの全ノズルからインクを吐出させる際にも前記圧力ポンプの加圧機能を用いるので、従来問題となっていたインク充填時や機能保全時の前記圧力緩衝器の破壊が発生しない。
【００３９】
また通常の印字動作中はインク供給路を介してインクが前記液滴噴射式記録ヘッドに供給されるので、前記圧力ポンプを常に作動させる必要はない。
【００４０】
さらに印字するために液滴噴射式記録ヘッドが移動する場合も移動しない場合も、印字品質を安定させるために、前記圧力緩衝器の設置は望ましいが、たとえ該圧力緩衝器がない場合でも前記インク供給路を用いれば、前記圧力ポンプを常に作動させる必要はない。
【００４１】
そして前記圧力ポンプが吸引機能と加圧機能の両方を具備する場合、該圧力ポンプの使用数を削減することができる。
【００４２】
これにより液滴噴射式記録ヘッドに加圧によってインク充填や機能保全を行う場合でも、問題なく圧力緩衝器を使用可能となり、前記液滴噴射式記録ヘッドに供給するインクの圧力のばらつきが抑制されるので、印字品質が安定するとともに、通常印字時に前記圧力ポンプを常時作動させなくてよいので、無駄なエネルギ−の消費を抑制することも可能となる。
【００４３】
さらに前記液滴噴射式記録ヘッドを交換する際に、該液滴噴射式記録ヘッドと前記インク供給路の連結を解除する前に、該液滴噴射式記録ヘッド内部に残留するインクを排除することができるので、周囲の環境を汚染しない。
【００４４】
図６に示す液滴噴射式記録装置５０の場合には、図２から図５に示す各要素の連通状態はそのままに、上記圧力ポンプ７の吸引機能を吸引ポンプ１６で実現すればよく、同様に上記圧力ポンプ７の加圧機能を加圧ポンプ１７で実現すればよい。
【００４５】
また図１から図６に記す廃液管にはインク排出を促進する吸引ポンプを具備していないが、当然該吸引ポンプを導入しても何ら問題はない。
【図面の簡単な説明】
【図１】本発明の実施形態に係る液滴噴射式記録装置を示す模式図である。
【図２】本発明のインク充填方法の過程を示す模式図である。
【図３】本発明のインク充填方法と機能保全方法の過程を示す模式図である。
【図４】本発明の通常印字時におけるインクの流れを示す模式図である。
【図５】本発明の液滴噴射式記録ヘッドからインクを排出する際のインクの流れを示す模式図である。
【図６】本発明の他の実施形態に係る液滴噴射式記録装置を示す模式図である。
【図７】従来技術に係る液滴噴射式記録装置を示す模式図である。
【符号の説明】
１、１００インク容器
２インク供給路
３、６、１１、１０４、１０７弁機構
４インク供給迂回路
５圧力緩衝器
７圧力ポンプ
８、１０６液滴噴射式記録ヘッド
９、１０５ノズル
１０、１０８ノズル開口面
１２インク排出管
１３受け部
１４廃液路
１５廃インク容器
１６吸引ポンプ
１７、１０１加圧ポンプ
１０２蓄圧部
１０３インク供給管
５０、２００液滴噴射式記録装置[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a droplet ejection type recording apparatus which is applied to, for example, a printer, a facsimile, etc., ejects droplets to a recording medium, and prints on the recording medium, and an ink filling method and a function preservation method.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a droplet ejection recording apparatus that records characters and images on a recording medium using a droplet ejection recording head having a plurality of nozzles that eject ink has been known. In such a droplet ejection type recording apparatus, before starting recording of characters and images on a recording medium, the droplet ejection type recording head is filled with ink, or the recording head is required to maintain print quality. It is necessary to maintain functions such as returning the droplet ejection type recording head to an initial state.
[0003]
FIG. 7 is a schematic view showing an example of a droplet ejection type recording apparatus 200 used for ink filling and function maintenance of such a droplet ejection type recording head.
[0004]
As shown in FIG. 7, in the related art, the droplet ejection type recording apparatus 200 includes an ink container 100, a pressure pump 101 for drawing ink from the ink container 100, and the pressure pump 101 fed by the pressure pump 101. A pressure accumulating unit 102 that holds the pressure of the ink therein until the pressure becomes equal to or higher than a predetermined value, and is provided between the pressure pump 101 and the pressure accumulating unit 102, and supplies the ink from the ink container 100 to the pressure accumulating unit 102. A valve mechanism 104 for appropriately opening and closing the ink supply path 103, a droplet ejection type recording head 106 having a nozzle 105, and an ink supply path 103 provided between the pressure accumulating unit 102 and the droplet ejection type recording head 106 A valve mechanism 107 for appropriately opening and closing the nozzle, a wiping device (not shown) for wiping a nozzle opening surface 108 where the nozzle 105 opens, All 05 are at least provided with a receiving portion (not shown) to cover in a plan view.
[0005]
The method of filling the ink into the droplet jet recording head 106 is as follows. First, the pressure pump 101 is operated with the valve mechanism 107 closed and the valve mechanism 104 opened, and ink is sent to the pressure accumulating section 102 to thereby accumulate the ink. The pressure inside 102 is increased. At the same time as the pressure inside the pressure accumulating unit 102 becomes sufficiently high, the valve mechanism 107 is opened, the valve mechanism 104 is closed, and the ink stored in the pressure accumulating unit 102 is transferred to the droplet ejection type recording head 106 using the pressure. Extrude and fill with impact. At this time, since the ink overflows from the nozzle 105 and the ink wets the nozzle opening surface 108, the overflowing ink is received by the receiving portion, and the ink that has wet the nozzle opening surface 108 is wiped by the wiping device (for example, see Patent Document 1). 1).
[0006]
In addition, the above-described method of filling the ink into the ink jet recording head 106 can be applied at the time of the maintenance in which the ink is ejected from all the nozzles 105 (for example, see Patent Document 2).
[0007]
[Patent Document 1]
JP-A-11-91128 (pages 2-4, FIG. 1)
[0008]
[Patent Document 2]
JP-A-11-207985 (page 2-3, FIG. 1)
[0009]
[Problems to be solved by the invention]
In such a droplet ejection recording apparatus, the ink filling method and the function preservation method, particularly in the case where the droplet ejection recording apparatus includes a pressure buffer on an ink supply path near the droplet ejection recording head. In addition to the shock-absorbing ink filling method and the function preserving method using the high pressure stored in the pressure accumulating unit in the droplet ejecting recording head as in the prior art, a pressure pump without using the pressure accumulating unit Only when using the ink filling method and the function preservation method, the pressure buffer cannot withstand the pressurizing pressure required for the ink filling method and the function preservation method. There has been a problem that the pressure buffer cannot be used.
[0010]
Here, the pressure buffer is fixed to the droplet ejection type recording head for the purpose of reducing the pressure fluctuation due to the inertial force of the ink due to the movement when the droplet ejection type recording head performs scanning and printing. When printing is performed by using the head, it is used for the purpose of alleviating the pressure fluctuation due to the impact or the like given to the head, and is an indispensable factor for maintaining good printing quality.
[0011]
Further, in the prior art, if there is a pressure pump such as a tube pump or the like that generates pressure by pressing the ink supply path by constantly contacting the pressure supply roller with the ink supply path and stopping the pressure pump, Since the pressure roller closes the ink supply path, it is necessary to continue to supply ink to the droplet ejection type recording head using the pressure pump even after the ink is filled, and the energy required for the supply is wasted. In the case where ink is further supplied by the pressure pump, the pressure of the supply becomes a pulsation, and the pulsation significantly impairs the print quality of a droplet jet recording head which cannot include the pressure buffer. The problem had occurred.
[0012]
In view of such circumstances, the present invention is directed to a liquid ejecting type recording apparatus which can be equipped with a pressure buffer even when performing a function maintenance operation such as filling a liquid ejecting type recording head with a pressure pump and performing full discharge. It is an object of the present invention to propose a configuration and a method of filling or maintaining the ink, and to propose a configuration of the droplet ejection type recording apparatus which does not need to always supply the ink by the pressure pump during normal printing.
[0013]
[Means for Solving the Problems]
An aspect of the present invention that solves the above-mentioned problems includes an ink container that stores ink therein, and a pressure reducing device that communicates with the ink container and reduces fluctuations in the supply pressure of the ink that is supplied to the droplet ejection recording head. An ink supply path including a buffer, a branch from the ink supply path at a position closer to the ink container than the pressure buffer, and the ink supply path between the pressure buffer and the droplet ejection type recording head; An ink supply bypass having at least one pressure pump, and a valve mechanism capable of appropriately switching a communication state between the ink supply bypass and the ink supply path. After the pressure buffer is filled with ink by a suction function that guides the ink by setting the target satisfying the negative pressure to the negative pressure, the valve mechanism is switched to pressurize the target filled with the ink of the pressure pump. The liquid droplet ejection type recording head is filled with ink or is entirely discharged by a pressurizing function for guiding the ink, and ink is supplied from an ink container through the ink supply path during normal printing. The present invention relates to an ejection type recording apparatus, and a method for filling ink and maintaining functions.
[0014]
In the droplet jet recording apparatus according to the present invention, the pressure buffer is filled with ink by the suction function, so that the pressure buffer is not destroyed, and the ink is filled in the droplet jet recording head by the press function. Or, since the entire ejection is performed, bubbles hardly remain in the head. Furthermore, if the pressure pumps used for the suction function and the pressurization function are shared, the pressure pumps can be integrated into one unit, and the number of pressure pumps used can be reduced. Therefore, it is possible to always maintain print quality in any type of droplet ejection type recording apparatus while realizing the manufacturing of the droplet ejection type recording apparatus at low cost.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail based on embodiments of the present invention.
[0016]
FIG. 1 is a schematic diagram showing a droplet ejection type recording apparatus 50, and shows an embodiment of the present invention. The configuration of the droplet ejection type recording apparatus 50 will be described.
[0017]
An ink container 1 for storing ink therein, and a droplet ejection type recording head via a pressure buffer 5, which alleviates fluctuations in the supply pressure of the ink supplied from the ink container 1 to the droplet ejection type recording head 8. An ink supply path 2 for supplying ink to the ink jet head 8, a valve mechanism 3 as a three-way valve installed at a position closer to the ink container 1 than an installation position of the pressure buffer 5, a pressure buffer 5, and a droplet jet recording head 8, a valve mechanism 6 serving as a three-way valve, an ink supply bypass 4 communicating the valve mechanism 6 with the valve mechanism 3, a pressure pump 7 provided on the ink supply bypass 4, A valve mechanism 11 as a three-way valve installed between the pressure pump 7 and the valve mechanism 3 on the supply bypass 4, and ink discharge for branching off the ink supply bypass 4 and discharging ink by the valve mechanism 11. The tube 12 and the droplet ejection type recording head 8 are provided. A nozzle opening surface 10 on which the nozzle 9 opens on the surface, a receiving portion 13 which is vertically opposed to the nozzle opening surface 10 and covers a plane area where all the nozzles 9 are distributed, and communicates with the bottom surface of the receiving portion 13 The droplet ejection type recording apparatus 50 is at least constituted by the waste liquid path 14, the ink discharge pipe 12, and the waste ink container 15 for storing the ink discharged from the waste liquid path 14.
[0018]
A in FIG. 1 indicates a vertical distance between the ink liquid level stored in the ink container 1 and the nozzle opening surface 10, which is a head difference for generating a pressure head required for forming a meniscus in the nozzle 9. is there. Since the pressure buffer 5 is provided for the purpose of suppressing the fluctuation of the pressure of the ink supplied to the droplet ejection type recording head 8, it is desirable to arrange the pressure buffering unit 5 as close to the droplet ejection type recording head 8 as possible. . In particular, in the case of the droplet ejection type recording apparatus 50 that performs printing by scanning the droplet ejection type recording head 8, the pressure buffer 5, the valve mechanism 6, and the droplet ejection type recording head 8 in the area shown by B in FIG. Must be mounted on the carriage.
[0019]
In the case of FIG. 1, the valve mechanism 3, the valve mechanism 6, and the valve mechanism 11 are all three-way valves, but the valve mechanism 3 and the valve mechanism 6 can appropriately select the communication state between the ink supply path 2 and the ink supply bypass circuit 4. Any element may be used. For example, there is no problem even in a configuration in which a plurality of on-off valves such as a solenoid valve are combined. Similarly, the valve mechanism 11 may be any element as long as the communication state between the ink supply bypass 4 and the ink discharge pipe 12 can be appropriately selected.
[0020]
The pressure pump 7 in FIG. 1 has both a suction function for guiding the ink to be filled with the ink to a negative pressure and guiding the ink, and a pressure function for pressing the target to be filled with the ink to guide the ink. This is a tube type pump that generates pressure by squeezing a tube with a pressure roller. Although only one pump is used, only a suction pump 16 having only a suction function as shown in FIG. A plurality of pressure pumps may be used by arranging the pressure pumps 17 in parallel with each other. Examples of the suction pumps and the pressure pumps that can be used here are the above-mentioned tube type pump and a diaphragm type for pressure-feeding ink. Pumps and piston-cylinder pumps for pumping ink are included.
[0021]
In the present invention, since the ink is filled into the droplet ejection type recording head 8 by pressurization, it is not necessary to close the nozzle 9 by bringing the receiving portion 13 into close contact with the nozzle opening surface 10, and the ink leaking from all the nozzles 9 is not required. It is sufficient to arrange the receiving portion 13 at a position where the receiving portion 13 can be received without leakage. Therefore, a driving device for moving the receiving portion 13 up and down is not required. In addition, since the ink is not sucked through the receiving portion 13 and the ink is not filled in the liquid droplet ejection type recording head 8, the waste liquid passage 14 does not need to be provided with a suction pump. There is no need for an air release valve to make the closed space with the air pressure equilibrium state with the atmospheric pressure.
[0022]
In addition, in the present invention, since the inside of the pressure buffer 5 is filled with ink by suction, even if the pressure buffer 5 is of a type having an air layer, the pressure buffer 5 may break while being filled with ink. There is no.
[0023]
Next, an ink filling method and a function preserving method for the droplet ejection recording head 8 in the droplet ejection recording apparatus 50 shown in FIG. 1 will be described with reference to FIGS.
[0024]
FIG. 2 shows a process of filling the pressure buffer 5 and the ink supply path 2 with ink, which is necessary before filling the ink into the droplet jet recording head 8.
[0025]
In FIG. 2, the ink supply path 2 and the ink supply bypass 4 are not connected by the valve mechanism 3, the ink container 1 and the pressure buffer 5 are connected by the valve mechanism 3, and the pressure buffer 5 is connected to the droplet ejection type by the valve mechanism 6. The recording head 8 is not connected, the pressure buffer 5 and the ink supply bypass 4 are connected, and the pressure pump 7 and the ink discharge pipe 12 are connected by the valve mechanism 11. In this state, the suction function of the pressure pump 7 is operated, and the ink flows from the ink container 1 in the direction of arrow C shown in FIG. 2, and the ink is discharged to the waste ink container 15 through the ink discharge pipe 12 for an appropriate time. Then, the pressure buffer 5 and the ink supply path 2 are evenly filled with ink.
[0026]
At this time, the ink discharge pipe 12 is an essential element for discharging the sucked ink from the ink supply bypass 4. Further, since the ink discharged from the ink discharge pipe 12 does not pass through the droplet ejection type recording head 8, it is unlikely that the ink contains fine dust and the like, and the ink discharged to the ink container 1 is not discharged to the waste ink container 15. It may be returned using the tube 12.
[0027]
FIG. 3 shows a process of filling the droplet jet recording head 8 with ink after completing the process shown in FIG.
[0028]
In FIG. 3, the ink supply path 2 and the ink supply bypass 4 are communicated without the ink container 1 and the pressure buffer 5 being communicated by the valve mechanism 3, and the pressure buffer 5 and the ink supply bypass circuit are communicated by the valve mechanism 6. 4, the ink supply bypass circuit 4 communicates with the droplet ejection type recording head 8, the valve mechanism 11 does not communicate the pressure pump 7 with the ink discharge pipe 12, and the pressure pump 7 communicates with the valve mechanism 3. are doing. In this state, the pressurizing function of the pressure pump 7 is operated, and the ink flows from the ink container 1 in the direction of arrow D shown in FIG. 3, and the ink is charged into the droplet ejecting recording head via the ink supply bypass 4. You. All the ink leaked from the nozzle 9 during the filling process is received by the receiving portion 13 and collected in the waste ink container 15 via the waste liquid passage 14.
[0029]
The most important point here is that after the process of filling the pressure buffer 5 shown in FIG. 2 with ink has been completed, the ink container 1 and the ink supply bypass 4 are first communicated by the valve mechanism 3 and the pressure buffer 5 And the ink container 1 is interrupted. The reason is that before the communication between the pressure buffer 5 and the ink container 1 is interrupted by the valve mechanism 3, the pressure buffer 5 and the droplet ejection type recording head 8 are communicated even instantaneously by the valve mechanism 6, and the pressure This is because, if the container 5 is opened to the atmosphere, the ink filled in the ink supply path 2 and the pressure buffer 5 escapes due to the action of gravity. If the communication between the pressure buffer 5 and the ink container 1 is interrupted by the valve mechanism 3 before the pressure buffer 5 is opened to the atmosphere, one end of the ink supply path 2 is closed, and the ink supply path 2 is closed. The ink filled in 2 and the pressure buffer 5 does not escape due to the action of gravity.
[0030]
FIG. 4 shows a process of supplying ink to the droplet ejection type recording head 8 in a state where the droplet ejection type recording head 8 normally prints after completing the process shown in FIG.
[0031]
In FIG. 4, the ink supply path 2 and the ink supply bypass 4 are not connected by the valve mechanism 3, but the ink container 1 and the pressure buffer 5 are connected by the valve mechanism 3, and the ink supply bypass 4 and droplet ejection are performed by the valve mechanism 6. The pressure buffer 5 and the droplet ejection type recording head 8 are communicated without communicating the type recording head 8. At this time, the state of the valve mechanism 11 may be any communication state. In this state, the path from the ink container 1 to the droplet ejecting recording head 8 is filled with ink. Therefore, if the droplet ejecting recording head 8 performs printing, the ink consumed in the printing naturally becomes ink container 1. Is supplied in the direction of arrow E from the same as in the case of a general well-known droplet ejection type recording apparatus.
[0032]
The order in which the valve mechanism 3 and the valve mechanism 6 are operated to ensure the communication between the pressure buffer 5 and the ink container 1 or the communication between the pressure buffer 5 and the droplet ejection type recording head 8 may be performed. Of course, the communication may be ensured by operating simultaneously.
[0033]
When the pressure buffer 5 and the ink container 1 are communicated with each other by the valve mechanism 3, the ink supply path is sealed by the valve mechanism 6, so that the ink is supplied from the ink supply path 2 including the pressure buffer 5. There is no backflow to the ink container 1, and even if the pressure buffer 5 and the droplet ejection type recording head 8 are communicated by the valve mechanism 6, a meniscus is formed in the nozzle 9 by the effect of the head difference A in FIG. This is because there is no problem.
[0034]
When the pressure buffer 5 and the droplet ejection type recording head 8 are communicated with each other by the valve mechanism 6, the ink supply path is closed by the valve mechanism 3. The ink does not come off from the nozzle 9 from the nozzle 2 by the action of gravity. Even if the pressure buffer 5 and the ink container 1 are thereafter communicated by the valve mechanism 3, the meniscus is applied to the nozzle 9 by the action of the head difference A in FIG. Is formed, so that there is no problem.
[0035]
After the ink filling in FIG. 3 is completed, ink remaining on the nozzle opening surface is wiped by a wiping member (not shown), and printing can be performed by connecting each element as shown in FIG.
[0036]
In order to maintain the print quality by ejecting ink from all the nozzles 9 during the normal printing of the droplet ejection type recording head 8, each element is communicated in the same state as shown in FIG. The ink may be pushed out by the pressurizing function of 7, and the operation order of the valve mechanism 3 and the valve mechanism 6 is not limited here.
[0037]
FIG. 5 shows a communication state of each element when the droplet ejection type recording head 8 is replaced. The valve mechanism 6 allows the pressure pump 7 to communicate with the droplet ejection type recording head 8, and the valve mechanism 11 allows the ink discharge pipe 12 to communicate with the pressure pump 7. Thereafter, if either the suction function or the pressure function of the pressure pump 7 is used, the ink flows in the direction of the double-headed arrow shown in FIG. 5, respectively, and the ink is discharged from the ink discharge pipe 12 or the nozzle 9. Here, when the ink is pushed out using the pressurizing function of the pressure pump, the ink remains on the surface of the nozzle opening surface 10, and it becomes necessary to wipe the ink with a wiping device (not shown). It is desirable that the ink be discharged from the ink discharge pipe 12.
[0038]
【The invention's effect】
As described above, in the present invention, after the ink is first filled in the pressure buffer provided in the ink supply path by the suction function of the pressure pump provided in the ink supply bypass, the liquid is supplied by the pressure function of the pressure pump. When the ink is filled in the droplet ejection type recording head, and the ink is ejected from all the nozzles of the droplet ejection type recording head, the pressurizing function of the pressure pump is used. Also, no destruction of the pressure buffer occurs during function maintenance.
[0039]
In addition, during normal printing operation, ink is supplied to the droplet ejection type recording head via the ink supply path, so that it is not necessary to always operate the pressure pump.
[0040]
In order to stabilize print quality, it is desirable to install the pressure buffer even when the droplet jet recording head moves or does not move for printing. If a supply path is used, it is not necessary to always operate the pressure pump.
[0041]
When the pressure pump has both a suction function and a pressurization function, the number of use of the pressure pump can be reduced.
[0042]
This makes it possible to use the pressure buffer without any problem even when performing ink filling and function maintenance by applying pressure to the droplet ejection recording head, and suppresses variations in the pressure of ink supplied to the droplet ejection recording head. Therefore, printing quality is stabilized, and the pressure pump does not need to be constantly operated during normal printing, so that it is possible to suppress wasteful energy consumption.
[0043]
Further, when replacing the droplet ejection type recording head, before disconnecting the connection between the droplet ejection type recording head and the ink supply path, the ink remaining inside the droplet ejection type recording head is eliminated. So that it does not pollute the surrounding environment.
[0044]
In the case of the droplet ejection type recording apparatus 50 shown in FIG. 6, the suction function of the pressure pump 7 may be realized by the suction pump 16 while the communication state of each element shown in FIGS. Then, the pressurizing function of the pressure pump 7 may be realized by the pressurizing pump 17.
[0045]
Although the waste liquid pipes shown in FIGS. 1 to 6 are not provided with a suction pump for promoting the discharge of ink, there is no problem if the suction pump is introduced.
[Brief description of the drawings]
FIG. 1 is a schematic diagram illustrating a droplet ejection type recording apparatus according to an embodiment of the present invention.
FIG. 2 is a schematic view illustrating a process of an ink filling method according to the present invention.
FIG. 3 is a schematic diagram showing the steps of an ink filling method and a function preservation method of the present invention.
FIG. 4 is a schematic diagram illustrating the flow of ink during normal printing according to the present invention.
FIG. 5 is a schematic diagram showing the flow of ink when discharging ink from a droplet jet recording head of the present invention.
FIG. 6 is a schematic view showing a droplet ejection type recording apparatus according to another embodiment of the present invention.
FIG. 7 is a schematic view showing a droplet ejection type recording apparatus according to the related art.
[Explanation of symbols]
1, 100 Ink container 2 Ink supply path 3, 6, 11, 104, 107 Valve mechanism 4 Ink supply bypass 5 Pressure buffer 7, Pressure pump 8, 106 Drop ejection type recording head 9, 105 Nozzle 10, 108 Nozzle opening Surface 12 Ink discharge pipe 13 Receiving part 14 Waste liquid path 15 Waste ink container 16 Suction pump 17, 101 Pressurizing pump 102 Pressure accumulating part 103 Ink supply pipe 50, 200 Droplet jet recording apparatus

Claims

An ink container for storing ink therein, an ink supply path communicating with the ink container for guiding the ink to a droplet ejecting recording head having a nozzle for ejecting the ink, and the droplet ejecting recording head A pressure buffer for reducing the supply pressure fluctuation of the ink supplied to the droplet ejection type recording head provided in the vicinity of the ink supply path, and a pressure buffer closer to the ink container than the pressure buffer. An ink supply detour branching off from an ink supply path and rejoining the ink supply path between the pressure buffer and the droplet ejection type recording head; and at least one ink provided in the ink supply detour And a valve mechanism that can appropriately select the communication between the ink container, the pressure buffer, the droplet ejection recording head, and the pressure pump. Droplet jet recording apparatus characterized by there.

The pressure pump has both a suction function for guiding the ink to a target to be filled with the ink at a negative pressure and a pressurizing function for guiding the ink by pressing the target to be filled with the ink. 2. The apparatus according to claim 1, wherein the number of the pressure pumps is one.

2. The droplet jet recording according to claim 1, wherein there are at least two types of pressure pumps dedicated to the suction function and the pressure function, and the pressure pumps are arranged in parallel. 3. apparatus.

An ink discharge pipe for discharging ink from the ink supply bypass is branched at a position closer to the ink container than the pressure pump installation position, and communication between the ink container and the pressure pump is provided at the branch point. 4. A droplet ejection type recording apparatus according to claim 1, wherein a valve mechanism is provided for enabling communication between an ink discharge pipe and the pressure pump to be appropriately selected.

An ink container for storing ink therein, an ink supply path communicating with the ink container for guiding the ink to a droplet ejecting recording head having a nozzle for ejecting the ink, and the droplet ejecting recording head A pressure buffer for reducing the supply pressure fluctuation of the ink supplied to the droplet jet recording head, the pressure supply being provided near the ink container, and An ink supply detour branching off from an ink supply path and rejoining the ink supply path between the pressure buffer and the droplet ejection type recording head; and at least one ink provided in the ink supply detour And a pressure pump for pressure-feeding the ink, wherein the ink container, the pressure buffer, and the pressure pump communicate with each other. The ink container, the pressure pump, and the liquid drop ejecting recording head are filled with the ink in a part or all of the inside of the pressure buffer by a suction function for guiding the ink by setting a target to be filled with the ink to a negative pressure. In a state in which the ink is filled, the ink is filled into the droplet ejection type recording head by a pressurizing function that pressurizes the object filled with the ink of the pressure pump and guides the ink, and after the filling is completed, the ink container and the ink container are filled. An ink filling method for a droplet ejection type recording apparatus, wherein a droplet ejection type recording head is communicated through the ink supply path.

6. The ink jet recording head according to claim 5, wherein after the pressure buffer is filled with ink, communication between the pressure buffer and the ink container is first interrupted, and then the droplet jet recording head is filled with ink. Ink-filling method for a liquid droplet ejection type recording apparatus.

When the pressure buffer is filled with ink, the ink guided by the suction function of the pressure pump is supplied to the pressure pump and the ink by a valve mechanism located on the ink supply bypass from the ink container to the pressure pump. Is discharged by connecting an ink discharge pipe for discharging the ink, and then guided from the ink container by the pressurizing function of the pressure pump by connecting the ink container and the pressure pump by the valve mechanism. 7. The ink filling method according to claim 5, wherein the ink is filled in the droplet ejection recording head.

An ink container for storing ink therein, an ink supply path communicating with the ink container for guiding the ink to a droplet ejecting recording head having a nozzle for ejecting the ink, and the droplet ejecting recording head A pressure buffer for reducing the supply pressure fluctuation of the ink supplied to the droplet jet recording head, the pressure supply being provided near the ink container, and An ink supply detour branching off from an ink supply path and rejoining the ink supply path between the pressure buffer and the droplet ejection type recording head; and at least one ink provided in the ink supply detour And a pressure pump for pressure-feeding the ink, when the ink is completely discharged from the nozzle, the ink container and the ink supply bypass And the droplet ejection type recording head are communicated with each other, and the ink is extruded by a pressurizing function that guides the ink by pressurizing an object filled with the ink by the pressure pump. Method.

An ink container for storing ink therein, an ink supply path communicating with the ink container for guiding the ink to a droplet ejecting recording head having a nozzle for ejecting the ink, and the droplet ejecting recording head A pressure buffer for reducing the supply pressure fluctuation of the ink supplied to the droplet jet recording head, the pressure supply being provided near the ink container, and An ink supply detour branching off from an ink supply path and rejoining the ink supply path between the pressure buffer and the droplet ejection type recording head; and at least one ink provided in the ink supply detour And a pressure pump for pressure-feeding, when replacing the droplet ejection recording head, the pressure of the ink container is higher than the pressure pump. By a valve mechanism on the ink supply bypass, an ink discharge pipe for discharging ink communicating with the pressure pump communicates with the droplet ejection type recording head, and the function of pumping the ink of the pressure pump causes the ink to be discharged. A method for maintaining the function of a droplet ejection type recording apparatus, comprising removing ink from the inside of the droplet ejection type recording head.